Islamic Fiqh > Marriage and family > Marriage impediments > First section: women permanently forbidden: the prohibition by blood relation
Contents
Updated on 25 September 2026 at 3:23 PM
This part belongs to the full section: All sections of this part.
The fiqh encyclopedia classifies the women forbidden in marriage (al-maharim) whose prohibition is permanent (mu'abbada): seven categories forbidden by blood relation, seven by breastfeeding, four by marriage affinity, the wife struck by li'an (mutual imprecation), the wives of the Prophet (peace be upon him), besides the wisdom of limiting wives to four and the rule on combining two women who are mahram to each other. Each sheet cites the positions of the four schools, the verses and hadiths with their takhrij (Bukhari, Muslim and others) and the classical references. The disputed cases of the daughter born of adultery, the milk engendered by intercourse, and the effect of adultery upon affinity are treated in detail.
The people of knowledge are unanimous: the women forbidden on account of blood relation are seven, mentioned in the Noble Quran, and the community has reached consensus on their prohibition.
1. The mothers, however high they may be:
"Forbidden to you are your mothers"
Surah An-Nisa, 23
The mothers are every woman to whom one is linked by birth, whether the name of mother applies to her literally, the one who gave birth to you, or figuratively: the one who gave birth to your father or your mother, however high she may be. This includes your two maternal and paternal grandmothers, the grandmothers of your grandmothers and the ancestors of your ancestors, however high they rise, whether they are heirs or not: all of them are forbidden mothers.
Abu Hurayra said of Hajar, the mother of Isma'il: "This is your mother, O sons of the water of the sky"Narrated by Bukhari (2179)
The sons of the water of the sky are a tribe among the Arabs. Allah forbade the paternal and maternal aunts, who are the daughters of grandfathers and grandmothers; the grandmothers are closer to them than the aunts, so their prohibition amounts to the prohibition of the grandmothers by the stronger reasoning, as the explicit prohibition of flirting carries that of insults and blows; upon this too the community has consensus (Bada'i al-Sana'i 2/256-257, al-Ikhtiyar 3/105, al-Jawhara al-Nayyira 4/270, al-Lubab 2/19).
The Imam Ibn Rushd said: they agreed that the "mother" here is a name for every female who has upon you a birth link through the mother's side or through the father's side; the "daughter" is a name for every female upon whom you have a birth link through the son, through the daughter, or directly (Bidayat al-Mujtahid 2/24; see also Ahkam al-Qur'an by Ibn al-Arabi 1/478, Tafsir al-Qurtubi 5/108, al-Furuq 3/215, al-Bayan 9/238, Rawdat al-Talibin 4/743, al-'Ubab 1007, al-Najm al-Wahhaj 7/153).
2. The daughters, however low they may descend, by the generality of the words of Allah "and your daughters" (An-Nisa, 23). The daughter is a name for every female upon whom you have a birth link; or one says: every woman whose lineage goes back to you by birth, at one degree or several, which brings into it the daughter of your loins, her daughters and the daughters of your sons, however low they descend. So the daughters of your daughters and the daughters of your sons are forbidden at all degrees, by the evidence of the text, for they are closer than the daughters of the brother and the daughters of the sister, and than the sisters themselves; the sisters are the children of the father while these are the children of his children, the mention of the prohibition there carrying this one by the stronger reasoning; upon this too consensus, except the daughter born of adultery (Bada'i al-Sana'i 2/257, al-Ikhtiyar 3/105, al-Jawhara al-Nayyira 4/270, al-Lubab 2/19, Bidayat al-Mujtahid 2/24, al-Mughni 7/84, Kashf al-Qina 5/75, Sharh Muntaha al-Iradat 5/155, Matalib Uli al-Nuha 5/88).
The jurists differed concerning the man who commits adultery with a woman who conceives a daughter from him: is this daughter forbidden to him as are the daughters whose descent is established from him, or is she not forbidden and does marriage become lawful to him? The question arises after two points of consensus: the child's descent is not established from the fornicator and the two do not inherit from each other; and a woman may not marry the son she bore from adultery, each inheriting from the other by consensus.
The majority of the jurists (Hanafis, Malikis in the well-known view, Hanbalis, and Shafi'is in one tendency): when a man commits adultery with a woman (may Allah protect) and she bears him a daughter, this daughter is forbidden to him as are the daughters whose descent is established from him. Their arguments: all of them were created from his semen, so she is a daughter or like a daughter, forbidden to him, to his ascendants and to his descendants, without being his stepdaughter; likewise the son born of his semen, whose daughter the man may not marry. And if she were his daughter she would inherit from him and he from her, and he could stay alone with her and compel her to marriage: all of that is excluded.
Likewise forbidden is the little girl nursed with the milk of a woman with whom a man committed adultery: as the daughter born of his adultery is not lawful to him, neither is she whom the milk born of that illicit intercourse has nursed, for the milk is his and the child is of his semen even if descent is not established.
"Forbidden to you are your mothers and your daughters"
Surah An-Nisa, 23
This daughter enters into the generality of the verse: she is a female created from his semen, a reality that does not change with lawfulness or prohibition; so she is forbidden to him as the woman who committed adultery is forbidden to her son born of adultery. It is also said: the "daughter of a man" is a name for a female actually created from his semen; she is therefore his daughter in reality, but the legal attribution to him is not admitted, so as not to spread the obscenity: this does not negate the real link, for realities are not retracted. Likewise inheritance and maintenance: the real link is established there, the Law having only suspended the legal establishment of descent there so that inheritance and maintenance flow for a meaning; whoever claims otherwise here must bring the proof.
Proving this is the report of the two shaykhs (Bukhari and Muslim) from Ibn Abbas: Hilal ibn Umayya slandered his wife before the Prophet (peace be upon him) concerning Sharik ibn Sahma.
The Prophet (peace be upon him) said: "Watch her: if she comes with a white child, of well-formed limbs and bright eyes, he will belong to Hilal ibn Umayya; if she comes with a child of dark eyes, thick eyelashes and crooked shins, he will belong to Sharik ibn Sahma", meaning the adulterer. She came with the child as described, and the Prophet said: "Were it not for what has already passed of the Book of Allah, there would be a grave matter between her and me"Narrated by Bukhari (4470) and Muslim (1496)
A further argument: she was created from his semen, a reality that does not change with lawfulness or prohibition, and she thus resembles the woman approached by mistake; she is a part of him, so she does not become lawful to him in marriage like his daughter; the absence of some rulings does not negate her being a daughter, as it would not if it were due to slavery or difference of religion.
Abd al-Razzaq reports from Ibn Jurayj: I was informed by Abu Bakr ibn Abd al-Rahman ibn Umm al-Hakam that a man asked: "O Messenger of Allah, I committed adultery with a woman in the Jahiliyya: may I marry her daughter?" He said: "I do not see that: it is not fitting for you to marry a woman who would look, from her daughter, at what you used to look at in her"Narrated by Abd al-Razzaq in his Musannaf (12784); a weak hadith, discontinuous and mursal
The Imam Ibn al-Qayyim said: the prohibition through the milk of the stallion proves the prohibition of the creature of the adulterer's semen in an even stronger way; for if it is forbidden for him to marry one who was nourished with milk that flowed through his intercourse, how could it be lawful for him to marry one created from that very semen and that very intercourse? And how could the Law forbid the daughter of suckling, where the man's intercourse is only the cause of the milk, then permit the one created from his very intercourse and semen? That is impossible: the partial link between him and the creature of his semen is more complete and more perfect than that with the milk-daughter, which contains only a portion of that link, whereas the creature of his semen is so, as her name indicates, in half of her or more.
This is the view of the majority of Muslims: no man is known among the Companions who permitted it. Imam Ahmad explicitly stated that whoever marries her is put to death by the sword, married or not. The milk-daughter is a daughter in only two respects: prohibition and inviolability; the absence of the other rulings of the daughter does not remove her from the prohibition: likewise the daughter of adultery is a daughter in the prohibition, her lacking the rulings not making her lawful (Zad al-Ma'ad 5/570).
Allah addressed the Arabs with what their languages understand: "daughter" is a linguistic term the Law has not transferred from its original usage, like "prayer" and "faith"; so it is taken in its linguistic sense until the transfer by the Lawgiver is established: "daughter", like "brother", "paternal uncle" and "maternal uncle", remains on its linguistic usage. It is established in the Sahih that Allah made the son of the adulterous shepherd speak: "My father is so-and-so the shepherd", a statement that cannot be a lie, and the community has consensus that his mother is forbidden to him: his creation is from the same semen as the adultery and their sin in it is the same; he is a part of him just as he is a part of her; and the severance of inheritance between the fornicator and the daughter does not make her marriage lawful.
Even more astonishing: the holder of this view forbids a man to use his hand upon himself (saying it is "the marriage of the hand"), permits a man to marry a part of himself, then permits him to bed the part that Allah created from his semen and brought out of his loins, as he would bed a foreign woman (Zad al-Ma'ad 5/570).
Ibn Qudama said: once this is established, there is no difference between his knowing she is from him, the case of a woman in purity whom he alone approached and then watched until she gave birth, and the case of a group who shared intercourse with a woman who bears a child without anyone knowing whose it is: she is forbidden to all of them, for two reasons. The first: she is the daughter of the woman they approached. The second: we know she is the daughter of one of them, so she is forbidden to all, as if two guardians married her without it being known which of them was first; she is forbidden also to their sons, being the sister of one of them without it being known which; if kinship ties her to one of them she becomes lawful to the sons of the others, without being lawful to any of those who approached her mother, for she is in reality his stepdaughter (al-Mughni 7/91-92).
Asked about a man who married his daughter born of adultery, Ibn Taymiyya answered: such a marriage is not permitted according to the majority of the imams of the Muslims; Imam Ahmad even denied that there was any dispute over it among the early generations and said: whoever does that will be killed. It was related to him that Malik permitted it: he declared that transmission a lie. This prohibition is the view of Abu Hanifa and his companions, of Ahmad and his companions, of Malik and the majority of his companions, and of many of the companions of al-Shafi'i; he denied that al-Shafi'i explicitly stated otherwise: he only stated the prohibition for the milk-daughter, not for the woman with whom one committed adultery (Majmu' al-Fatawa 32/142).
Asked whether the daughter of adultery may be given in marriage to her father, he answered: praise be to Allah, the view of the majority of scholars is that such a marriage is not permitted, and it is the indisputably correct view; to the point that the majority dispute whether the one who does it is put to death, on two views. What is transmitted from Ahmad is that he is put to death: that is said of one who does not resort to interpretation (ta'wil); the interpreter is not put to death even though he is mistaken. Or it is said absolutely, as the majority say of the drinker of the disputed nabidh: flogged even if he is not deemed wicked according to al-Shafi'i and Ahmad in one narration, while Malik and Ahmad in the other declare him wicked; the correct view is that the excused interpreter is not wicked, nor even sinful. Ahmad had not known of any dispute over this issue: it appeared only in his time, not in the time of the early generations, which is why he did not know it (Majmu' al-Fatawa 32/134, 137).
The argument of those who permitted marriage with the daughter of adultery: she is not a daughter under the Law, since neither mutual inheritance, nor obligatory maintenance, nor taking charge of her marriage, nor emancipation through ownership, nor the other rulings of descent are established; not being a daughter under the Law she does not enter the verse of prohibition and remains under the words "and lawful to you is what is beyond that" (An-Nisa, 24).
The argument of the majority: the words of Allah "forbidden to you are your mothers, your daughters..." (An-Nisa, 23) embrace everyone embraced by the term, whether literally or figuratively, whether inheritance and the other rulings are established or only the prohibition; the generality of the verse of prohibition is not like the generality of the verse of shares "Allah enjoins you concerning your children: for the male the like of the share of two females" (An-Nisa, 11), for three reasons. The first: the verse of prohibition covers the daughter, the son's daughter and the daughter's daughter, as the term "paternal aunt" covers the sister of the father, of the mother and of the grandfather, likewise the sister's daughter, the sister's son's daughter and the sister's daughter's daughter: a generality found neither in the verse of shares nor in similar texts. The second: the prohibition of marriage is established by breastfeeding alone: "suckling forbids what descent forbids" (or "what birth forbids"), a hadith whose authenticity is agreed upon and which the imams applied: Allah forbade the woman the child she nursed and his sons, forbade those to her mothers, aunts and cousins, and forbade the nursed little girl the stallion who owns the milk, the one who had intercourse with the woman until the milk flowed; if the prohibition holds for the milk-daughter, with no ruling of descent besides the prohibition, how could the daughter created from his semen be permitted?
The third reason: "the wives of your sons from your loins" (An-Nisa, 23): a precaution excluding the adopted son, as in "so that there may not be any difficulty for the believers in marrying the wives of their adopted sons when they have accomplished with them what they had to" (Al-Ahzab, 37); and in the Jahiliyya the Arabs would attach the child of adultery more than the adopted child: Allah having restricted that with "from your loins", it is known that the term daughters and similar terms embrace everything that, in their language, falls under the name.
To the claim "inheritance is not established in her favor", the answer is that the rulings of descent are distributed: some are established without others, as most of the parties to li'an agree that the child is forbidden to the imprecator without inheriting from him; and the scholars disputed the attachment of the child of adultery when there is no marriage bed, on two views: the Prophet attached the child of Walida bint Zam'a to Zam'a ibn al-Aswad although Utba ibn Abi Waqqas had conceived him with her; Sa'd and Abd ibn Zam'a disputed, the first saying: my brother's son entrusted me that this child of Walida bint Zam'a is my son, the second: my brother and the son of my father's brother, born on my father's bed. The Prophet said: "He is yours, O Abd ibn Zam'a: the child belongs to the bed, and to the adulterer the stone; veil yourself from him, O Sawda", seeing his evident resemblance to Utba: he made him a brother in inheritance, without the prohibition of marriage.
The scholars also disputed whether the child of adultery is emancipated through ownership, on two views in the schools of Abu Hanifa and Ahmad; such a weak issue may not be narrated from any imam of the Muslims, whether in criticism or in following: that would be a form of attacking the imams and following weak views; the vizier of the Tatars acted likewise to sow discord between the schools of the people of the sunna, call them out of the sunna and the community and cast them into the doctrines of the Rafidites and the heretics (Majmu' al-Fatawa 32/134, 137).
Asked about a man who committed adultery in his youth and sees today with the woman a girl he seeks in marriage without knowing whether she is his, Ibn Taymiyya answered: marriage is not lawful to him according to most scholars; the daughter the woman bore to another man is not lawful to him according to Abu Hanifa, Malik and Ahmad in one narration; the daughter of adultery is graver still; and if the two are confused for him, both are forbidden (Majmu' al-Fatawa 32/138).
The Shafi'is of the madhhab and some Malikis, such as Ibn al-Majishun, the qadi Abd al-Wahhab and al-Qurtubi: it is disliked for him to marry his daughter born of adultery, though she is not forbidden. They say: if he commits adultery with a woman who bears a daughter from the semen of his adultery, she becomes lawful to him without being forbidden: marriage is permitted, for she is a foreign woman to him; no prohibition attaches to the semen of adultery, as shown by the absence, by consensus, of mutual inheritance, descent and every ruling of birth; so marriage is like with a foreign woman, whether she consented to the adultery or not, whether it is certain she is of his semen or not; only the marriage is disliked, to avoid the dispute or because she may be of him.
Al-Shafi'i said: "I dislike that he marry her; if he marries her I do not annul it." It is also said: she is forbidden absolutely. Or: she is forbidden if it is certain she is of his semen, through the information of a prophet (as in the time of Isa, peace be upon him) or because he kept her from the adultery until the birth. If a woman nursed a little girl with the milk of the fornicator, she becomes like his daughter. The son of adultery is forbidden to his mother and to her mahram by consensus, as he inherits from her; the difference is that the son is a part of her that became a separate person, which is not the case with the drop from which the daughter was created with respect to the father.
The Imam al-Nawawi said: a derived issue: a man committed adultery with a woman who bore a daughter: may the fornicator marry her? He may, but it is disliked; it is said: if it is certain she is of his semen she is forbidden; it is said: she is forbidden absolutely. The correct view is lawfulness absolutely, whether she consented to the adultery or was coerced (Rawdat al-Talibin 4/744, al-Bayan 9/256-257, al-Najm al-Wahhaj 7/153-154, Mughni al-Muhtaj 4/290-291, al-Dibaj 3/239, Tuhfat al-Muhtaj 8/691).
The Maliki qadi Abd al-Wahhab said: if he commits adultery with a woman who bears a daughter, marriage with her is disliked for the fornicator without being forbidden, contrary to Abu Hanifa, by the words of the Prophet (peace be upon him): "The child belongs to the bed, and to the adulterer the stone": he restricted that no ruling attaches to his act, she being foreign to him, as shown by the other rulings specific to birth (descent, obligatory maintenance, guardianship over body and property, testimony) not being established here; likewise the prohibition of marriage (al-Ishraf 3/325-326, no. 1162).
The Imam Ibn Abd al-Barr said: the jurists differed over the meaning of this hadith regarding a man's marriage to his daughter born of adultery or his paternal sister born of adultery: a group forbade it, among them Ibn al-Qasim, and it is the view of Abu Hanifa and his companions; others permitted it, among them Abd al-Malik ibn al-Majishun; and it is the view of al-Shafi'i with dislike: "what is more beloved to me is to abstain from it", by the words "veil yourself from him, O Sawda"; he does not annul it if it takes place; the same is related from Malik; his proof is "the child belongs to the bed": he denied that the child belongs to any bed other than the man's, and it is far-fetched that the adulterer has anything (al-Tamhid 1/191, Tafsir al-Qurtubi 13/60).
The Imam al-Qurtubi said: the jurists differed over a man's marriage to his daughter born of adultery, his sister or his son's daughter born of adultery: a group forbade it, among them Ibn al-Qasim, and it is the view of Abu Hanifa and his companions; others permitted it, among them Abd al-Malik ibn al-Majishun, and it is the view of al-Shafi'i; this was treated at length under women. In the tafsir of Surat al-Nisa he adds: among the arguments of the other view is the Prophet's information (peace be upon him) concerning Jurayj and his words: "O boy, who is your father? He said: so-and-so the shepherd" (narrated by Muslim 2550): this shows that adultery forbids as lawful intercourse does, so that the mother of the nursed child of adultery and her daughters would not be lawful to the fathers of the fornicator nor to his sons; this is the narration of Ibn al-Qasim in al-Mudawwana; the same hadith shows that the creature of the fornicator's semen does not become lawful to him: this is the well-known view.
Abd al-Malik ibn al-Majishun said: she is lawful, and that is correct, by the words of Allah:
"It is He who created man from water, then made for him kinship by blood and marriage"
Surah Al-Furqan, 54
meaning through a valid marriage (Tafsir al-Qurtubi 5/115-116). The reliance on that hadith for these two issues: the Prophet (peace be upon him) related that Jurayj attributed the child of adultery to the fornicator, and Allah confirmed that attribution with the miracle of the child's speech testifying to it, the Prophet announcing it in a context of praise and honor: the attribution was therefore correct by Allah's confirmation and the Prophet's information, and sonship with its rulings is established. If it is objected that inheritance, guardianship and the rest should then follow, whereas the Muslims agreed there is no inheritance between them: the answer is that this confirms what we said: the rulings upon which consensus was formed are excepted, and the rest remains on the basis of that proof (Tafsir al-Qurtubi 5/115-116).
Ibn al-Qayyim said: al-Shafi'i explicitly stated the dislike of marriage with the daughter of the adulterer's semen and never said it is lawful or permitted; what befits his grandeur, his imamate and the rank Allah raised him to in religion is that this dislike be in the sense of prohibition: he used the term dislike because Allah and His Messenger dislike the unlawful (I'lam al-Muwaqqi'in 1/42-43).
Here is the rest of the seven women forbidden by blood relation. 3. The sisters, of whatever side: full, consanguine or uterine, by the generality of the words of Allah "and your sisters" (An-Nisa, 23): the "sister" is a name for every female who shares with you one of your two roots, the father or the mother, or both.
4. The paternal aunts, all of them, by the words of Allah "and your paternal aunts" (An-Nisa, 23): the name covers every woman who is a sister of your father, and every woman who is a sister of any male who has upon you a birth link. Forbidden is whoever bears the name of paternal aunt literally, his father's sister, full, consanguine or uterine; and whoever bears the name figuratively: every sister of any of his grandfathers through the father or through the mother. The paternal aunts are the sisters of the father from the three sides, and the sisters of the grandfathers through the father and through the mother, near or far, heir or not: so forbidden are his paternal aunt, that of his father, of his mother, of his grandfather and of his grandmother, by consensus (Bada'i al-Sana'i 2/257, Bidayat al-Mujtahid 2/24, al-Bayan 9/239, al-Mughni 7/84, Sharh Muntaha al-Iradat 5/156, Manar al-Sabil 2/571).
5. The maternal aunts, all of them, by the words of Allah "and your maternal aunts" (An-Nisa, 23), whether full, consanguine or uterine, by the unrestricted application of the name. Forbidden is whoever bears the name of maternal aunt literally, his mother's sister, full, consanguine or uterine; and whoever bears it figuratively: the sister of any of his grandmothers through the mother or through the father. So forbidden are his maternal aunt full, consanguine or uterine, that of his mother at these three degrees, and that of his grandmother, by consensus: the maternal aunts are the sisters of the mother from the three sides and the sisters of the grandmothers however high they rise, for every grandmother is a mother, so every sister of a grandmother is a forbidden maternal aunt (same references).
6. The daughters of the brother, however low they descend, by consensus, by the words of Allah "the daughters of the brother" (An-Nisa, 23): forbidden is the brother's daughter literally, the daughter of his loins; and figuratively: every woman linked to his brother by descent through his sons and his daughters, however low they descend (Bada'i al-Sana'i 2/257, Bidayat al-Mujtahid 2/24, al-Bayan 9/239, al-Mughni 7/84, Sharh Muntaha al-Iradat 5/156, Manar al-Sabil 2/571).
7. The daughters of the sister, however low they descend, by consensus, by the words of Allah "the daughters of the sister" (An-Nisa, 23): forbidden is the sister's daughter literally, the daughter of her loins; and figuratively: every woman linked to his sister by descent through the daughters of her sons and her daughters, however low they descend.
"Forbidden to you are your mothers, your daughters, your sisters, your paternal aunts, your maternal aunts, the daughters of your brother and the daughters of your sister"
Surah An-Nisa, 23
All of these are forbidden by the text of the Book of Allah and by consensus (except the daughter of adultery), in marriage, intercourse and its preliminaries, permanently. The text affirmed the prohibition absolutely: it therefore requires the prohibition of every act toward them, except the act of veneration and honor, excluded from the intent of prohibition: either because it is commanded by the texts enjoining the maintenance of kinship ties and kindness to parents, or required by reason or consensus. The other relatives are lawful by the words of Allah "and lawful to you is what is beyond that" (An-Nisa, 24) (al-Ikhtiyar 3/105, Bada'i al-Sana'i 2/257, Bidayat al-Mujtahid 2/24, al-Bayan 9/239, al-Mughni 7/84, Sharh Muntaha al-Iradat 5/156).
The people of knowledge agree: what descent forbids is forbidden by breastfeeding, by the words of Allah "your mothers who nursed you and your sisters through suckling" (An-Nisa, 23).
Ibn Abbas said: the Prophet (peace be upon him) said concerning the daughter of Hamza: "She is not lawful to me: suckling forbids what descent forbids; she is the daughter of my brother through suckling"Narrated by Bukhari (2502) and Muslim (1447)
This hadith shows that suckling is a cause of prohibition and stands as descent in establishing the prohibition: descent forbids through the reality of the shared substance or its likeness, and suckling contains the likeness of the shared substance through the milk, which is part of the human body, growing the flesh and forming the bone (al-Mabsut 5/132).
Amra bint Abd al-Rahman reports that Aisha told her that the Messenger of Allah (peace be upon him) was with her when she heard a man asking permission to enter Hafsa's house. She said: I said: O Messenger of Allah, here is a man asking to enter your house. The Prophet said: "I think it is so-and-so", Hafsa's paternal uncle through suckling. Aisha said: if he were alive, would you let him enter upon you? He said: "Yes: suckling forbids what birth forbids"Narrated by Bukhari (4811) and Muslim (1444)
Urwa ibn al-Zubayr reports from Aisha: Aflah asked permission to enter upon me and I did not grant it. He said: do you veil yourself from me while I am your uncle? I said: how so? He said: your brother's wife nursed you with your brother's milk. I said: I asked the Messenger of Allah (peace be upon him) about that, and he said: "Aflah has spoken the truth, grant him permission"Narrated by Bukhari (2501) and Muslim (1445)
The Imam Abu Bakr al-Jassas said: the revealed text on suckling mentions the mothers and sisters through suckling; but it is established from the Prophet (peace be upon him), by a mass-transmitted, knowledge-compelling report, that he said: "suckling forbids what descent forbids", and the jurists agreed to apply it (Ahkam al-Qur'an 3/69).
The Imam al-Nawawi said: these hadiths agree on the establishment of the prohibition through suckling; the community has consensus on the prohibition between the nursed child and the wet nurse: he becomes her son, marriage is forbidden forever, but the look, seclusion and travel with her are lawful to him; none of the rulings of motherhood follow in any respect: they do not inherit from each other, maintenance is not obligatory on either, emancipation through ownership does not attach, his testimony is not barred for her, he does not take charge of her marriage, the law of retaliation does not lapse if he kills her: they are like two strangers in these rulings. The community also agreed on the spread of the prohibition between the wet nurse and the children of the nursed child, and between the nursed child and the children of the wet nurse: he is in that like her child by descent, on account of these hadiths (Sharh Sahih Muslim 1019).
Seven are forbidden by suckling as by descent: the mothers, the daughters, the sisters, the paternal aunts, the maternal aunts, the brothers' daughters and the sisters' daughters. When a woman nurses a child with the milk of a husband, the nursed child becomes the son of both her and the husband: the milk arises from her through a cause attributed to the husband, so the nursed child is their son as one born of them; the wet nurse thus becomes his mother, her mothers his grandmothers through the mother, her fathers his grandfathers through the mother, her daughters his sisters through the mother, her brothers his maternal uncles, her sisters his maternal aunts; and the husband becomes his father, the husband's fathers his grandfathers through the father, his mothers his grandmothers through the father, the sons of the husband's brothers his cousins, his brothers his paternal uncles and his sisters his paternal aunts: the ranks of descent unfold as we described for blood kinship, and the women forbidden by suckling are seven as those forbidden by descent, with the same derivatives.
So the father's sister through suckling becomes a forbidden paternal aunt, whether she is a sister by descent or by suckling; likewise the grandfather's sister and his father's sister through suckling, forbidden like the paternal aunt; the mother's sister through suckling becomes a forbidden maternal aunt, whether a sister by descent or by suckling; likewise the grandmother's sister and her mother, forbidden like the maternal aunt. On this basis, the ruling of the other kinships through suckling is referred to the ruling of kinships by descent (al-Hawi al-Kabir 9/198-199).
The Imam Ibn al-Mundhir said: they also agreed that suckling forbids what descent forbids (al-Ijma' 375). They also agreed that the unmarried girl whose milk flowed and who nursed a child: the child is her son and has no father through suckling (al-Ijma' 376).
Ibn Qudama said: every woman forbidden by descent is forbidden likewise by suckling: the mothers, the daughters, the sisters, the paternal aunts, the maternal aunts, the brothers' daughters and the sisters' daughters, as explained under descent, by the words of the Prophet (peace be upon him): "suckling forbids what descent forbids" (agreed upon), and in Muslim's wording: "suckling forbids what birth forbids". The Prophet said of Durra bint Abi Salama: "Were she not my stepdaughter in my home, she would have been lawful to me: she is the daughter of my brother through suckling; Thuwayba nursed me and her father" (agreed upon): the mothers and sisters are mentioned in the text, the rest enter the generality of the term of the forbidden women; we know of no disagreement over this (al-Mughni 7/87).
Ibn Battal said: there is no disagreement in the community: suckling forbids what descent forbids, by the words of Allah "your mothers who nursed you and your sisters through suckling" (An-Nisa, 23); the mother through suckling being forbidden, her husband likewise: he becomes father to the one his wife nursed, for the milk is from both; the husband's brother becomes an uncle and the wife's sister a maternal aunt. Forbidden through suckling: the paternal aunts, the maternal aunts, the paternal uncles, the maternal uncles, the sisters and their daughters, as by descent: that is the meaning of "suckling forbids what birth forbids".
Ibn al-Mundhir said: when a man's wife nurses a girl, she is forbidden to his son, his father, his grandfather, his sons' sons and daughters' daughters, to every son of a son and son of a daughter, and to every grandfather through the father and through the mother; if the nursed child is a boy, Allah forbids him the children of the woman who nursed him and the children of the man whose milk nursed the boy, that is, the wet nurse's husband; his paternal aunt and maternal aunt through suckling are not lawful to him, nor the brother's daughter nor the sister's daughter through suckling (Sharh Sahih al-Bukhari 7/93).
The Hanafis: likewise everyone whom the four categories forbid through affinity is forbidden through suckling, to the point that there is forbidden to the one who had intercourse the mother of the woman he approached and her daughter through suckling; the woman approached is forbidden to the intercourse-doer's father and son through suckling; the wife of the father through suckling is forbidden to his son through suckling; and the wife of the son through suckling is forbidden to the father through suckling.
Al-Kasani said: likewise everyone whom the four categories forbid through marriage affinity is forbidden through suckling: forbidden to the man are his wife's mother and her daughter through suckling, the mother being forbidden by the mere valid contract and the daughter only by consummation with the mother, as in descent; likewise the wife's grandmothers through her father and mother, however high they rise, and the daughters of her daughters and of her sons, however low they descend, through suckling. Forbidden likewise to the grandfather through suckling is the wife of the grandson through suckling and of the great-grandson through suckling, however low they descend; and forbidden to the son through suckling and his grandson is the wife of the father through suckling and of his father, however high they rise.
Forbidden likewise through intercourse to the one who had it are the mother of the woman approached and her daughter through suckling, as well as her grandmothers and the daughters of her daughters; the woman approached is forbidden to the intercourse-doer's father and son through suckling, to his grandfathers however high and to the sons of his sons however low, whether the intercourse was lawful through slave ownership, a corrupt marriage or its likeness, or adultery. The principle: suckling forbids what descent and affinity forbid, except two issues where the rulings of affinity and suckling differ (Bada'i al-Sana'i 2/262, Tuhfat al-Fuqaha 2/124).
Al-Kasani says further: the wet nurse is forbidden to the nursed child, for she has become his mother through suckling, by the words of the Prophet "your mothers who nursed you" (An-Nisa, 23) placed in apposition to "forbidden to you are your mothers and your daughters": Allah named the wet nurse the mother of the nursed child and forbade her to him; likewise her daughters are forbidden to him, whether from the owner of the milk or from another, earlier or later, for they are his sisters through suckling, Allah having said "and your sisters through suckling" (An-Nisa, 23): He established brotherhood between the wet nurse's daughters and the nursed child and the prohibition between them absolutely, without distinguishing one sister from another; likewise her granddaughters and the daughters of her sons, however low they descend, for they are the daughters of the brother and sister of the nursed child through suckling, forbidden by descent as by suckling.
If a woman nurses two children of strangers, they become brothers: being children of the wet nurse, marriage is not fitting between them if one is a female. The principle: two children who shared one breast become brothers, sisters, or brother and sister through suckling: neither may marry the other nor the other's children, as in descent. The wet nurse's mothers are forbidden to the nursed child, for they are his grandmothers through the mother by suckling; her fathers are his grandfathers by suckling and are forbidden as in descent. The wet nurse's sisters are forbidden to the nursed child, for they are his maternal aunts by suckling, and her brothers his maternal uncles, forbidden as in descent; as for the daughters of the wet nurse's brothers and sisters, they are not forbidden to the nursed child: they are the daughters of his maternal uncles and aunts by suckling, just as they are not forbidden by descent.
The wet nurse is forbidden to the nursed child's sons and the sons of his sons, however low they descend, as in descent: that is the explanation of the prohibition on the wet nurse's side. The principle is the words of the Prophet (peace be upon him): "suckling forbids what descent forbids": the generality must be applied except what a specific proof has restricted (Bada'i al-Sana'i 4/2-3).
Ibn Battal reports from Ibn al-Mundhir: there is no harm in a man marrying the woman who nursed his son; likewise he may marry that woman's daughter, who is the nursed child of his son; the nursed boy's brother may marry the woman who nursed his brother, and her daughter, the nursed child of his brother, and whoever he wishes of her children and her children's children: only marriage with these women is forbidden to the nursed child. This is the madhhab of Malik, of the Kufans, of al-Shafi'i and of Abu Thawr (Sharh Sahih al-Bukhari 7/194-195).
The jurists of the four schools agree: the milk engendered by intercourse forbids what descent forbids: when a woman nurses a child with the milk that arose from a man's intercourse, this child is forbidden to this man, the woman's husband, and to his relatives, as his son by descent is forbidden. The report of Amra bint Abd al-Rahman from Aisha and the report of Aflah already cited prove it, as does this version: Aisha said: my uncle through suckling asked permission to enter upon me and I refused to grant it until I had asked the Messenger of Allah (peace be upon him). When he entered I asked him, and he said: "He is your uncle, grant him permission". I said: O Messenger of Allah, it is the woman who nursed me, not the man. He said: "He is your uncle, let him stay with you". Aisha added: this after the veil was imposed upon us; and she said: suckling forbids what birth forbids (narrated by Bukhari 4941).
Aisha had been nursed with the milk of Abu al-Qays's wife, from his milk: Abu al-Qays became a father to her and his brother an uncle; this troubled her, for there is no true suckling except from a woman, the words of Allah mentioning only "your mothers who nursed you and your sisters through suckling"; hence her question, and the Prophet informed her that the milk of the stallion forbids by his answer: "He is your uncle, grant him permission".
Ibn al-Mundhir said: the sunna suffices, without the rest; and rationally the cause of the milk is the seed of the man and the woman together: suckling must therefore come from both as the child comes from both, whatever the difference in their causes; as the grandfather, the cause of the child, had the prohibition of his child's child attached to him like that of his child. Ibn Abbas was asked about a man with two wives, one nursing a boy and the other a girl, and said: "The marriage of the boy to the girl is not fitting: the begetting is one": the mothers, though distinct, have one father, the cause of the milk of both women: the boy and the girl are brother and sister through the father by suckling (Sharh Sahih al-Bukhari by Ibn Battal 7/201, Ahkam al-Qur'an by al-Jassas 3/69).
Abu Umar ibn Abd al-Barr said of Aisha's hadith: it is the clearest thing in this chapter and the strongest in exposition, removing the doubt: do you not see Aisha's words "it is the woman who nursed me, not the man", so that he would be my father and his brother my uncle; the Messenger of Allah (peace be upon him) answered her: when the woman nursed you she became your mother, and her husband, the cause of her milk, your father, and his brother your uncle. Aisha understood what she had not known before and said: "suckling forbids what birth forbids"; had the uncle been like the milk-father, had she been nursed together with her father Abu Bakr by one woman, no such teaching would have been needed (al-Istidhkar 6/242-243, al-Tamhid 8/242 and 22/155).
By the words of Allah "your mothers who nursed you and your sisters through suckling" (An-Nisa, 23): the mother through suckling being forbidden, her husband likewise: he becomes father to the one his wife nursed, for the milk is from both; the brother of the one who nursed becomes an uncle and her sister a maternal aunt. Forbidden through suckling: the paternal aunts, the maternal aunts, the paternal uncles, the maternal uncles, the sisters and their daughters, as by descent: that is the meaning of "suckling forbids what birth forbids". Ibn al-Mundhir said: when a man's wife nurses a girl, she is forbidden to his son, his father, his grandfather, his sons' sons and daughters' daughters, to every son of a son, to every grandfather through the father and through the mother; if the nursed child is a boy, Allah forbids him the children of the woman who nursed him and the children of the man whose milk nursed him, that is, the wet nurse's husband; his paternal aunt and maternal aunt through suckling are not lawful to him, nor the brother's daughter nor the sister's daughter (Sharh Sahih al-Bukhari 7/193).
The Imam al-Nawawi said: as for the man to whom this milk is attributed because he is the woman's husband, or because he had intercourse with her by slave ownership or likeness: our madhhab and that of all the scholars is the establishment of the prohibition through suckling between him and the nursed child, who becomes his son; the man's children are the nursed child's brothers and sisters; the man's brothers his paternal uncles and his sisters his paternal aunts; the nursed child's children are the man's children. Opposed in this only by the literalists (ahl al-zahir) and Ibn Ulayya, who hold that the prohibition through suckling is not established between the man and the nursed child; al-Maziri transmitted this from Ibn Umar and Aisha. Their proof is the words of Allah "your mothers who nursed you and your sisters through suckling" (An-Nisa, 23): He did not mention the daughter and the paternal aunt as He did in descent. The majority argue with these authentic explicit hadiths concerning Aisha's uncle and Hafsa's uncle, together with the Prophet's words upon granting permission: "suckling forbids what birth forbids"; and they answer the invocation of the verse that it contains no text permitting the daughter and the aunt: the mention of a thing does not show the removal of the ruling from what is other than it without an opposing proof: how much less with these authentic hadiths (Sharh Sahih Muslim 10/19).
Ibn Qudama said: when a woman nurses a child with milk that arose from a man's intercourse, this child is forbidden to the man and his relatives as his son by descent is forbidden: the milk is from the man as it is from the woman: the child becomes the man's son and he his father; the man's children his brothers and sisters, whether from that woman or another; the man's brothers and sisters his paternal uncles and aunts; his fathers and mothers his grandfathers and grandmothers. Ahmad said: the milk of the stallion: if a man has two wives, one nursing a girl and the other a boy, the two may not marry. Ibn Abbas was asked about a man with two slave women, one nursing a girl and the other a boy, and said: "No: the begetting is one".
Al-Tirmidhi said: this explains the milk of the stallion; among those who held its prohibition: Ali, Ibn Abbas, Ata', Tawus, Mujahid, al-Hasan, al-Sha'bi, al-Qasim, Urwa, Malik, al-Thawri, al-Awza'i, al-Shafi'i, Ishaq, Abu Ubayd, Abu Thawr, Ibn al-Mundhir and the people of opinion. Ibn Abd al-Barr said: to this went the jurists of the regions of the Hijaz, Iraq and Syria, and the group of the people of hadith (al-Mughni 7/78, 88).
Those who permitted the milk of the stallion: Sa'id ibn al-Musayyib, Abu Salama ibn Abd al-Rahman, Sulayman ibn Yasar, Ata' ibn Yasar, al-Nakha'i and Abu Qilaba; it is also related from Ibn al-Zubayr and a group of unnamed Companions of the Messenger of Allah, for suckling is from the woman, not from the man. It is also related from Zaynab bint Abi Salama that Asma bint Abi Bakr, wife of al-Zubayr, nursed her: al-Zubayr would enter upon her while she combed her hair, take hold of a horn of her head and say: come to me and talk to me; she saw in him a father, and her children were her siblings. Then Abdallah ibn al-Zubayr proposed, through Hamza ibn al-Zubayr, son of al-Kalbiyya, the marriage of Umm Kultum, his daughter. She said to his messenger: would she be lawful to him, she being the daughter of his father's brother? Abdallah said: I only meant by this withholding what you met with; those Asma bore are your siblings, those not from Asma are no siblings to you: go and ask. She sent and asked while the Companions of the Messenger of Allah (peace be upon him) were gathered; they said: "Suckling from the man's side forbids nothing": so she married her daughter to him, and she remained with him until he died.
Our proof is the report of Aisha: "Aflah, the brother of Abu al-Qays, asked permission to enter upon me after the veil was imposed; I said: by Allah, I will not grant him permission until I have asked the Messenger of Allah (peace be upon him), for the brother of Abu al-Qays is not the one who nursed me: it was the wife of Abu al-Qays who nursed me. The Messenger of Allah entered and I said: O Messenger of Allah, the man is not the one who nursed me: it was his wife. He said: 'Grant him permission: he is your uncle, may your right hand be rubbed with dust'". Urwa said: Aisha then took as rule: "forbid through suckling what descent forbids" (agreed upon): a decisive text on the point of dispute: what contradicts it is not relied upon. As for Zaynab's hadith, if authentic it is a proof for us: al-Zubayr believed they were his children and they believed he was their father; it appears this was well known among them; his statement, with the approval of the people of his time, outweighs his son's statement and that of unidentified people.
Muhammad ibn al-Hasan said: as for the milk of the stallion, we hold it forbidding, and we hold that suckling forbids what descent forbids: the brother through suckling from the father has forbidden to him his sister through suckling from the father, even if the two mothers are different, if the milk of both comes from one man, as Ibn Abbas said: "the begetting is one": this we hold, and it is the view of Abu Hanifa (al-Muwatta according to Muhammad ibn al-Hasan 2/580; see Mukhtasar Ikhtilaf al-Ulama 2/318).
The Imam al-Kasani said: as for the prohibition on the side of the wet nurse's husband from whom the milk flowed, it is established according to most of the scholars and most of the Companions (may Allah be pleased with them). Rafi' ibn Khadij related that it is not established, as Sa'id ibn al-Musayyib, Ata' ibn Yasar, Busr al-Marisi and Malik: this is the issue famous among the jurists under the name "the milk of the stallion": does it forbid or not? The explanation of its prohibition: the nursed girl is forbidden to the wet nurse's husband, for she is his daughter through suckling; likewise to the sons he had from another wife, who are her brothers through the father by suckling; likewise to the sons of his sons and of his daughters from another wife, who are the sons of the nursed girl's brothers and sisters through the father by suckling.
On this basis, if a man has two wives who both conceive from him and each of whom nurses a foreign child, the two children become brothers through the father by suckling: if one is a female, marriage between them is not fitting; if they are two females, a man may not combine them, for they are two sisters through the father by suckling. They are forbidden to the fathers of the wet nurse's husband, grandfathers through the father by suckling, and to his brothers, paternal uncles of the nursed child through suckling, his sisters its paternal aunts; as for the sons of the husband's brothers and sisters, marriage among them is fitting: they are the sons of uncles and aunts, whose marriage is lawful in descent, so in suckling: that is the explanation of the milk of the stallion.
The argument of the one who says it does not forbid: Allah clarified the prohibition on the wet nurse's side and not on the husband's, by "your mothers who nursed you" (An-Nisa, 23); had the prohibition been established on his side, He would have clarified it as He did in descent with "forbidden to you are your mothers and your daughters"; and that which forbids is the suckling, which occurs from her, not from him: so she becomes a daughter of hers, not of his. Proof: if milk flowed to the husband and a child nursed from it, she would not be forbidden to him: his own milk not establishing the prohibition, how would another's? Our proof: the famous hadith "suckling forbids what descent forbids", then the hadiths of Aisha; and Ibn Abbas, asked about a man with two wives, or a slave woman and a wife, one of whom nursed a boy and the other a girl: is the marriage of the boy to the girl fitting? said: "No: the begetting is one": he stated the ruling and pointed to the meaning, the oneness of the begetting; that which forbids is the milk, whose cause is the seed of the man and the woman together: suckling must therefore come from both as the child came from both.
As for their claim that Allah clarified the prohibition on the wet nurse's side, not on her husband's: if not by explicit text, then by indication: Allah's clarification is twofold, comprehensive or sufficient: He clarified descent comprehensively and suckling sufficiently, leaving the mujtahids to exercise ijtihad and to reason from the case mentioned to the unmentioned: the prohibition on the wet nurse's side lies in the milk, whose cause and flow come from both waters together: so suckling is from both together; milk brings about the prohibition only through the shared substance and partial link, growing the flesh and forming the bone as the hadith states; the cause of the milk being the two waters together, the partial link is established through suckling by the growth of flesh: the cause stands in place of the reality of the link in prohibitions as a precaution; and the cause stands in place of the caused especially in prohibitions: a woman is forbidden to her grandfather as to her father, though her prohibition to the grandfather is not mentioned in the Noble Book: the grandfather being the cause of the father's seed, the cause stands in place of the caused in the prohibition as a precaution: so it is here.
Proof: the daughter through suckling not being mentioned in the text, the daughters of brothers and sisters through suckling were not mentioned either: only the sisters were named, their daughters being forbidden by indication, by consensus: so it is here: if He did not clarify it by recited revelation, He clarified it by unreccited revelation upon the tongue of the Messenger of Allah (peace be upon him): "suckling forbids what descent forbids". Their argument that suckling occurs only from her is answered: it occurs from both of them, the cause of the milk being the two waters together. As for milk that flows to the husband from which a child nurses: that is not called suckling by custom, and the meaning of suckling, the child's sufficiency in nourishment, is not realized by it: it does not spare him hunger, like sheep's milk. The prohibition on the husband's side is only established if he is her husband; if she has no husband, as a woman who bore from adultery and whose milk flowed to nurse a child: the suckling is from her alone, not from the fornicator, for his descent is established from her alone; the principle: descent and suckling are established from the same source: from whomever descent is established, suckling is established; from whomever it is not, neither is suckling. Likewise the virgin whose milk flowed without ever having married: the suckling is from her alone (Bada'i al-Sana'i 4/3-4).
Ibn Rushd said: seventh issue: does the man to whom the milk is attributed, that is, the woman's husband, become a father to the nursed child, so that what is forbidden between fathers and sons by descent is forbidden between the two of them and on their side; this is what is called the milk of the stallion? They differed: Malik, Abu Hanifa, al-Shafi'i, Ahmad, al-Awza'i and al-Thawri say the milk of the stallion forbids; a group says it does not forbid: the first view is that of Ali and Ibn Abbas, the second that of Aisha, Ibn al-Zubayr and Ibn Umar. The cause of their disagreement is the apparent conflict of the Book with the famous hadith of Aisha: "Aflah, the brother of Abu al-Qays, came asking permission to enter upon me after the veil was imposed; I refused to grant it and asked the Messenger of Allah (peace be upon him), who said: he is your uncle, grant him permission. I said: O Messenger of Allah, it is the woman who nursed me, not the man. He said: he is your uncle, let him stay with you": narrated by Bukhari, Muslim and Malik.
Whoever holds that what the hadith contains is a law added to what the Book contains, by the words of Allah "your mothers who nursed you and your sisters through suckling" (An-Nisa, 23) and the words of the Prophet "suckling forbids what birth forbids", says the milk of the stallion forbids. Whoever holds that the verse of suckling and the Prophet's words came only to establish the ruling of suckling, the deferral of clarification being not permitted beyond the time of need, says: if that hadith were applied literally it would abrogate these foundations, for an alteration that changes the ruling is abrogating; moreover Aisha's school, the narrator of the hadith, was not the prohibition through the milk of the stallion; and it is difficult to overturn by rare hadiths the widespread foundations meant to establish and clarify at the time of need, especially those that are evident: hence Umar said, concerning the hadith of Fatima bint Qays: "We do not abandon the Book of Allah for the report of a woman" (Bidayat al-Mujtahid 2/29).