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Surah 4. An-Nisaa'
Ayah 19 - 21
19يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ لَا يَحِلُّ لَكُمْ أَن تَرِثُوا۟ ٱلنِّسَآءَ كَرْهًا ۖ وَلَا تَعْضُلُوهُنَّ لِتَذْهَبُوا۟ بِبَعْضِ مَآ ءَاتَيْتُمُوهُنَّ إِلَّآ أَن يَأْتِينَ بِفَـٰحِشَةٍ مُّبَيِّنَةٍ ۚ وَعَاشِرُوهُنَّ بِٱلْمَعْرُوفِ ۚ فَإِن كَرِهْتُمُوهُنَّ فَعَسَىٰٓ أَن تَكْرَهُوا۟ شَيْـًٔا وَيَجْعَلَ ٱللَّهُ فِيهِ خَيْرًا كَثِيرًا
20وَإِنْ أَرَدتُّمُ ٱسْتِبْدَالَ زَوْجٍ مَّكَانَ زَوْجٍ وَءَاتَيْتُمْ إِحْدَىٰهُنَّ قِنطَارًا فَلَا تَأْخُذُوا۟ مِنْهُ شَيْـًٔا ۚ أَتَأْخُذُونَهُۥ بُهْتَـٰنًا وَإِثْمًا مُّبِينًا
21وَكَيْفَ تَأْخُذُونَهُۥ وَقَدْ أَفْضَىٰ بَعْضُكُمْ إِلَىٰ بَعْضٍ وَأَخَذْنَ مِنكُم مِّيثَـٰقًا غَلِيظًا
[19-21] O Believers, it is not lawful for you to become the heirs of widows by force:28 nor is it lawful that you should treat your wives harshly in order to deprive them of a part of the dowry you have given them. However (you have the right to treat them harshly), if they are guilty of adultery.29 You should live with them in an honorable manner, even if you dislike them; it is possible that Allah may bring much good to you through that very thing you dislike.30 And if you make up your mind to marry another wife in place of the one you already have, do not take back anything out of what you have given her. even though it may have been a heap of wealth. Will you take it back by slander and gross injustice? And how is it proper for you to take it, when both of you have enjoyed conjugal happiness and she received from you a solemn pledge of union?31
28This means that the widow of the deceased should not be regarded as a part of his inheritance. After the death of the husband, his widow is quite free to live wherever she likes and to marry whomever she chooses after the expiry of her term.
29That is, "You may hurt them for immoral conduct but not for grabbing their wealth."
30If the wife is not beautiful or has some other defect that might not be to the husband's liking, it is not right that he should make up his mind to get rid of her at once without any further consideration. He should behave coolly and patiently. She may have some other redeeming qualities that may be more conducive to a happy married life than beautiful looks. It is just possible that the discovery of those qualities might change his repulsion at first sight into attraction. In the same way, sometimes it so happens that in the beginning of married life, the husband takes a dislike to something in the wife and feels a repulsion towards her but if he is patient with her and lets her show her better side fully, he himself realizes that her good qualities more than compensate for her shortcomings. "therefore it is not right for the husband to cut off his relations with his wife without a good deal of thinking. Divorce is the very last thing to which one may resort as a necessary social surgery and that, too, only when it becomes absolutely inevitable. The Holy Prophet says that of all the lawful things, divorce is the most reprehensible thing in the sight of Allah. In another Tradition, he admonishes, An-Nisa "Enter into marriage and divorce not, for Allah does not approve of such men and women as divorce and marry for mere sexual enjoyment."
31"Solemn pledge" is the marriage bond on the guarantee of which a woman gives herself up to a man. Therefore, if the man breaks that pledge of his own accord, he has no right to get back what he gave her as dower at the time of making that pledge. (Please see E.N.251, Al-Baqarah, also).