AN NISAA' — Ayat 24
وَالْمُحْصَنَاتُ مِنَ النِّسَاء إِلاَّ مَا مَلَكَتْ أَيْمَانُكُمْ كِتَابَ اللّهِ عَلَيْكُمْ وَأُحِلَّ لَكُم مَّا وَرَاء ذَلِكُمْ أَن تَبْتَغُواْ بِأَمْوَالِكُم مُّحْصِنِينَ غَيْرَ مُسَافِحِينَ فَمَا اسْتَمْتَعْتُم بِهِ مِنْهُنَّ فَآتُوهُنَّ أُجُورَهُنَّ فَرِيضَةً وَلاَ جُنَاحَ عَلَيْكُمْ فِيمَا تَرَاضَيْتُم بِهِ مِن بَعْدِ الْفَرِيضَةِ إِنَّ اللّهَ كَانَ عَلِيمًا حَكِيمًا
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.
Tafsir Ibnu Katsir
وَالْمُحْصَنَـتُ مِنَ النِّسَآءِ إِلاَّ مَا مَلَكْتَ أَيْمَـنُكُمْ كِتَـبَ اللَّهِ عَلَيْكُمْ وَأُحِلَّ لَكُمْ مَّا وَرَاءَ ذَلِكُمْ أَن تَبْتَغُواْ بِأَمْوَلِكُمْ مُّحْصِنِينَ غَيْرَ مُسَـفِحِينَ فَمَا اسْتَمْتَعْتُمْ بِهِ مِنْهُنَّ فَـَاتُوهُنَّ أُجُورَهُنَّ فَرِيضَةً وَلاَ جُنَاحَ عَلَيْكُمْ فِيمَا تَرَاضَيْتُمْ بِهِ مِن بَعْدِ الْفَرِيضَةِ إِنَّ اللَّهَ كَانَ عَلِيماً حَكِيماً
24. Also (forbidden are) women already married, except those (slaves) whom your right hands possess. Thus has Allah ordained for you. All others are lawful, provided you seek them (with a dowry) from your property, desiring chastity, not fornication. So with those among them whom you have enjoyed, give them their required due, but if you agree mutually (to give more) after the requirement (has been determined), there is no sin on you. Surely, Allah is Ever All-Knowing, All-Wise. Allah said,