Read Ruku 65 of the Quran

۞ وَٱلْمُحْصَنَـٰتُ مِنَ ٱلنِّسَآءِ إِلَّا مَا مَلَكَتْ أَيْمَـٰنُكُمْ ۖ كِتَـٰبَ ٱللَّهِ عَلَيْكُمْ ۚ وَأُحِلَّ لَكُم مَّا وَرَآءَ ذَٰلِكُمْ أَن تَبْتَغُوا۟ بِأَمْوَٰلِكُم مُّحْصِنِينَ غَيْرَ مُسَـٰفِحِينَ ۚ فَمَا ٱسْتَمْتَعْتُم بِهِۦ مِنْهُنَّ فَـَٔاتُوهُنَّ أُجُورَهُنَّ فَرِيضَةًۭ ۚ وَلَا جُنَاحَ عَلَيْكُمْ فِيمَا تَرَٰضَيْتُم بِهِۦ مِنۢ بَعْدِ ٱلْفَرِيضَةِ ۚ إِنَّ ٱللَّهَ كَانَ عَلِيمًا حَكِيمًۭا ﴿٢٤﴾

And [also prohibited to you are all] married women except those your right hands possess. [This is] the decree of Allah upon you. And lawful to you are [all others] beyond these, [provided] that you seek them [in marriage] with [gifts from] your property, desiring chastity, not unlawful sexual intercourse. So for whatever you enjoy [of marriage] from them, give them their due compensation as an obligation. And there is no blame upon you for what you mutually agree to beyond the obligation. Indeed, Allah is ever Knowing and Wise.

وَمَن لَّمْ يَسْتَطِعْ مِنكُمْ طَوْلًا أَن يَنكِحَ ٱلْمُحْصَنَـٰتِ ٱلْمُؤْمِنَـٰتِ فَمِن مَّا مَلَكَتْ أَيْمَـٰنُكُم مِّن فَتَيَـٰتِكُمُ ٱلْمُؤْمِنَـٰتِ ۚ وَٱللَّهُ أَعْلَمُ بِإِيمَـٰنِكُم ۚ بَعْضُكُم مِّنۢ بَعْضٍۢ ۚ فَٱنكِحُوهُنَّ بِإِذْنِ أَهْلِهِنَّ وَءَاتُوهُنَّ أُجُورَهُنَّ بِٱلْمَعْرُوفِ مُحْصَنَـٰتٍ غَيْرَ مُسَـٰفِحَـٰتٍۢ وَلَا مُتَّخِذَٰتِ أَخْدَانٍۢ ۚ فَإِذَآ أُحْصِنَّ فَإِنْ أَتَيْنَ بِفَـٰحِشَةٍۢ فَعَلَيْهِنَّ نِصْفُ مَا عَلَى ٱلْمُحْصَنَـٰتِ مِنَ ٱلْعَذَابِ ۚ ذَٰلِكَ لِمَنْ خَشِىَ ٱلْعَنَتَ مِنكُمْ ۚ وَأَن تَصْبِرُوا۟ خَيْرٌۭ لَّكُمْ ۗ وَٱللَّهُ غَفُورٌۭ رَّحِيمٌۭ ﴿٢٥﴾

And whoever among you cannot [find] the means to marry free, believing women, then [he may marry] from those whom your right hands possess of believing slave girls. And Allah is most knowing about your faith. You [believers] are of one another. So marry them with the permission of their people and give them their due compensation according to what is acceptable. [They should be] chaste, neither [of] those who commit unlawful intercourse randomly nor those who take [secret] lovers. But once they are sheltered in marriage, if they should commit adultery, then for them is half the punishment for free [unmarried] women. This [allowance] is for him among you who fears sin, but to be patient is better for you. And Allah is Forgiving and Merciful.