Surah An-Nisa Verse 20 - English Translation by Muhammad Sarwar
Surah An-Nisaوَإِنۡ أَرَدتُّمُ ٱسۡتِبۡدَالَ زَوۡجٖ مَّكَانَ زَوۡجٖ وَءَاتَيۡتُمۡ إِحۡدَىٰهُنَّ قِنطَارٗا فَلَا تَأۡخُذُواْ مِنۡهُ شَيۡـًٔاۚ أَتَأۡخُذُونَهُۥ بُهۡتَٰنٗا وَإِثۡمٗا مُّبِينٗا
If you want to divorce a woman so that you can marry another, do not take back the dowry which you had paid even if what you paid was a large amount of gold. To do this is a slanderous act and a manifest sin