What does « When / If » mean in the Quran?

And when it is said to them, "Believe in what Allah has revealed," they say, "We believe [only] in what was revealed to us." And they disbelieve in what came after it, while it is the truth confirming that which is with them. Say, "Then why did you kill the prophets of Allah before, if you are [indeed] believers?"

Originator of the heavens and the earth. When He decrees a matter, He only says to it, "Be," and it is.

And if you brought to those who were given the Scripture every sign, they would not follow your qiblah. Nor will you be a follower of their qiblah. Nor would they be followers of one another's qiblah. So if you were to follow their desires after what has come to you of knowledge, indeed, you would then be among the wrongdoers.

Who, when disaster strikes them, say, "Indeed we belong to Allah, and indeed to Him we will return."

And when it is said to them, "Follow what Allah has revealed," they say, "Rather, we will follow that which we found our fathers doing." Even though their fathers understood nothing, nor were they guided?

Righteousness is not that you turn your faces toward the east or the west, but [true] righteousness is [in] one who believes in Allah, the Last Day, the angels, the Book, and the prophets and gives wealth, in spite of love for it, to relatives, orphans, the needy, the traveler, those who ask [for help], and for freeing slaves; [and who] establishes prayer and gives zakah; [those who] fulfill their promise when they promise; and [those who] are patient in poverty and hardship and during battle. Those are the ones who have been true, and it is those who are the righteous.

Prescribed for you when death approaches [any] one of you if he leaves wealth [is that he should make] a bequest for the parents and near relatives according to what is acceptable - a duty upon the righteous.

And when My servants ask you, [O Muhammad], concerning Me - indeed I am near. I respond to the invocation of the supplicant when he calls upon Me. So let them respond to Me [by obedience] and believe in Me that they may be [rightly] guided.

And complete the Hajj and 'umrah for Allah. But if you are prevented, then [offer] what can be obtained with ease of sacrificial animals. And do not shave your heads until the sacrificial animal has reached its place of slaughter. And whoever among you is ill or has an ailment of the head [making shaving necessary must offer] a ransom of fasting [three days] or charity or sacrifice. And when you are secure, then whoever performs 'umrah [during the Hajj months] followed by Hajj [offers] what can be obtained with ease of sacrificial animals. And whoever cannot find [or afford such an animal] - then a fast of three days during Hajj and of seven when you have returned [home]. Those are ten complete [days]. This is for those whose family is not in the area of al-Masjid al-Haram. And fear Allah and know that Allah is severe in penalty.

There is no blame upon you for seeking bounty from your Lord [during Hajj]. But when you depart from 'Arafat, remember Allah at al- Mash'ar al-Haram. And remember Him, as He has guided you, for indeed, you were before that among those astray.

And when you have completed your rites, remember Allah like your [previous] remembrance of your fathers or with [much] greater remembrance. And among the people is he who says, "Our Lord, give us in this world," and he will have in the Hereafter no share.

And when he goes away, he strives throughout the land to cause corruption therein and destroy crops and animals. And Allah does not like corruption.

And when it is said to him, "Fear Allah," pride in the sin takes hold of him. Sufficient for him is Hellfire, and how wretched is the resting place.

And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."

And when you divorce women and they have [nearly] fulfilled their term, either retain them according to acceptable terms or release them according to acceptable terms, and do not keep them, intending harm, to transgress [against them]. And whoever does that has certainly wronged himself. And do not take the verses of Allah in jest. And remember the favor of Allah upon you and what has been revealed to you of the Book and wisdom by which He instructs you. And fear Allah and know that Allah is Knowing of all things.

And when you divorce women and they have fulfilled their term, do not prevent them from remarrying their [former] husbands if they agree among themselves on an acceptable basis. That is instructed to whoever of you believes in Allah and the Last Day. That is better for you and purer, and Allah knows and you know not.

Mothers may breastfeed their children two complete years for whoever wishes to complete the nursing [period]. Upon the father is the mothers' provision and their clothing according to what is acceptable. No person is charged with more than his capacity. No mother should be harmed through her child, and no father through his child. And upon the [father's] heir is [a duty] like that [of the father]. And if they both desire weaning through mutual consent from both of them and consultation, there is no blame upon either of them. And if you wish to have your children nursed by a substitute, there is no blame upon you as long as you give payment according to what is acceptable. And fear Allah and know that Allah is Seeing of what you do.

And those who are taken in death among you and leave wives behind - they, [the wives, shall] wait four months and ten [days]. And when they have fulfilled their term, then there is no blame upon you for what they do with themselves in an acceptable manner. And Allah is [fully] Acquainted with what you do.

And if you fear [an enemy, then pray] on foot or riding. But when you are secure, then remember Allah [in prayer], as He has taught you that which you did not [previously] know.

O you who have believed, when you contract a debt for a specified term, write it down. And let a scribe write [it] between you in justice. Let no scribe refuse to write as Allah has taught him. So let him write and let the one who has the obligation dictate. And let him fear Allah, his Lord, and not leave anything out of it. But if the one who has the obligation is of limited understanding or weak or unable to dictate himself, then let his guardian dictate in justice. And bring to witness two witnesses from among your men. And if there are not two men [available], then a man and two women from those whom you accept as witnesses - so that if one of the women errs, then the other can remind her. And let not the witnesses refuse when they are called upon. And do not be [too] weary to write it, whether it is small or large, for its [specified] term. That is more just in the sight of Allah and stronger as evidence and more likely to prevent doubt between you, except when it is an immediate transaction which you conduct among yourselves. For [then] there is no blame upon you if you do not write it. And take witnesses when you conclude a contract. Let no scribe be harmed or any witness. For if you do so, indeed, it is [grave] disobedience in you. And fear Allah. And Allah teaches you. And Allah is Knowing of all things.

So how will it be when We assemble them for a Day about which there is no doubt? And each soul will be compensated [in full for] what it earned, and they will not be wronged.

She said, "My Lord, how will I have a child when no man has touched me?" [The angel] said, "Such is Allah; He creates what He wills. When He decrees a matter, He only says to it, 'Be,' and it is.

Here you are loving them but they are not loving you, while you believe in the Scripture - all of it. And when they meet you, they say, "We believe." But when they are alone, they bite their fingertips at you in rage. Say, "Die in your rage. Indeed, Allah is Knowing of that within the breasts."

And those who, when they commit an immorality or wrong themselves [by transgression], remember Allah and seek forgiveness for their sins - and who can forgive sins except Allah? - and [who] do not persist in what they have done while they know.

And Allah had certainly fulfilled His promise to you when you were killing the enemy by His permission until [the time] when you lost courage and fell to disputing about the order [given by the Prophet] and disobeyed after He had shown you that which you love. Among you are some who desire this world, and among you are some who desire the Hereafter. Then he turned you back from them [defeated] that He might test you. And He has already forgiven you, and Allah is the possessor of bounty for the believers.