وَإِنْ أَرَدتُّمُ ٱسْتِبْدَالَ زَوْجٍ مَّكَانَ زَوْجٍ وَءَاتَيْتُمْ إِحْدَىٰهُنَّ قِنطَارًا فَلَا تَأْخُذُوا۟ مِنْهُ شَيْـًٔا ۚ أَتَأْخُذُونَهُۥ بُهْتَـٰنًا وَإِثْمًا مُّبِينًا Qur’an An-Nisaa' (4:20)Wain aradtumu istibd a la zawjin mak a na zawjin wa a taytum i h d a hunna qin ta ran fal a takhu th oo minhu shayan atakhu th oonahu buht a nan waithman mubeen a n
I.e., by falsely accusing her of immoral conduct in the hope of regaining her dower (see note [18] above).
Lit., "if you desire the exchange of a wife in place of a wife and you have given one of them a treasure (qintar), do not take away anything thereof". The allusion to the "exchange" of one wife for another is a clear indication of the Qur'anic view that a monogamous marriage is the desirable norm.
Treasure: Qintar = a Talent of gold: see iii. 14, first note.