2:231
وَإِذَا طَلَّقْتُمُ ٱلنِّسَآءَ فَبَلَغْنَ أَجَلَهُنَّ فَأَمْسِكُوهُنَّ بِمَعْرُوفٍ أَوْ سَرِّحُوهُنَّ بِمَعْرُوفٍۢ ۚ وَلَا تُمْسِكُوهُنَّ ضِرَارًۭا لِّتَعْتَدُوا۟ ۚ وَمَن يَفْعَلْ ذَٰلِكَ فَقَدْ ظَلَمَ نَفْسَهُۥ ۚ وَلَا تَتَّخِذُوٓا۟ ءَايَٰتِ ٱللَّهِ هُزُوًۭا ۚ وَٱذْكُرُوا۟ نِعْمَتَ ٱللَّهِ عَلَيْكُمْ وَمَآ أَنزَلَ عَلَيْكُم مِّنَ ٱلْكِتَٰبِ وَٱلْحِكْمَةِ يَعِظُكُم بِهِۦ ۚ وَٱتَّقُوا۟ ٱللَّهَ وَٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ بِكُلِّ شَىْءٍ عَلِيمٌۭ
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.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
Being Kind to the Divorced Wife
This is a command from Allah to men that when one of them divorces his wife with a reversible divorce, he should treat her kindly. So when her term of `Iddah (waiting period) nears its end, he either takes her back in a way that is better, including having witnesses that he has taken her back, and he lives with her with kindness. Or, he should release her after her `Iddah finishes and then kindly asks her to depart from his house, without disputing, fighting with her or using foul words. Allah then said:
وَلاَ تُمْسِكُوهُنَّ ضِرَارًا لِّتَعْتَدُواْ
(But do not take them back to hurt them,)
Ibn `Abbas, Mujahid, Masruq, Al-Hasan, Qatadah, Ad-Dahhak, Ar-Rabi` and Muqatil bin Hayyan said that a man used to divorce his wife, and when her `Iddah came near its end, he would take her back to harm her and to stop her from marrying someone else. He then divorced her and she would begin her `Iddah and when her `Iddah term neared its end, he would take her back again, so that the term of `Iddah would be prolonged for her. After that, Allah prohibited this practice. Allah has also threatened those who indulge in such practices, when He said;
وَمَن يَفْعَلْ ذَلِكَ فَقَدْ ظَلَمَ نَفْسَهُ