An-Nisa 4:20

وَإِنْ أَرَدتُّمُ ٱسْتِبْدَالَ زَوْجٍ مَّكَانَ زَوْجٍ وَءَاتَيْتُمْ إِحْدَىٰهُنَّ قِنطَارًا فَلَا تَأْخُذُوا۟ مِنْهُ شَيْـًٔا ۚ أَتَأْخُذُونَهُۥ بُهْتَـٰنًا وَإِثْمًا مُّبِينًا

Wa-in aradttumu is'tib'dāla zawjin makāna zawjin waātaytum iḥ'dāhunna qinṭāran falā takhudhū min'hu shayan atakhudhūnahu buh'tānan wa-ith'man mubīnan

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?