وَاِنۡ اَرَدتُّمُ اسۡتِبۡدَالَ زَوۡجٍ مَّكَانَ زَوۡجٍ ۙ وَّاٰتَيۡتُمۡ اِحۡدٰٮهُنَّ قِنۡطَارًا فَلَا تَاۡخُذُوۡا مِنۡهُ شَيۡـــًٔا ؕ اَ تَاۡخُذُوۡنَهٗ بُهۡتَانًا وَّاِثۡمًا مُّبِيۡنًا(النساء :20)
Wain aradtumu istibdala zawjin makana zawjin waataytum ihdahunna qintaran fala takhuthoo minhu shayan atakhuthoonahu buhtanan waithman mubeenan
Sahih International:
But if you want to replace one wife with another and you have given one of them a great amount [in gifts], do not take [back] from it anything. Would you take it in injustice and manifest sin?
وَ كَيۡفَ تَاۡخُذُوۡنَهٗ وَقَدۡ اَفۡضٰى بَعۡضُكُمۡ اِلٰى بَعۡضٍ وَّاَخَذۡنَ مِنۡكُمۡ مِّيۡثَاقًا غَلِيۡظًا(النساء :21)
Wakayfa takhuthoonahu waqad afda ba'dukum ila ba'din waakhathna minkum meethaqan ghaleethan
Sahih International:
And how could you take it while you have gone in unto each other and they have taken from you a solemn covenant?
Complete Indexing of Quran Topics
We have indexed and found 2 verses about or related to (including the word(s)) "Marriage, Mahr not to be taken back in case of divorce".
For your information, the verses as described above: