Surah An-Nisa Verse 20 - English Translation by Dr Munir Munshey
Surah An-Nisaوَإِنۡ أَرَدتُّمُ ٱسۡتِبۡدَالَ زَوۡجٖ مَّكَانَ زَوۡجٖ وَءَاتَيۡتُمۡ إِحۡدَىٰهُنَّ قِنطَارٗا فَلَا تَأۡخُذُواْ مِنۡهُ شَيۡـًٔاۚ أَتَأۡخُذُونَهُۥ بُهۡتَٰنٗا وَإِثۡمٗا مُّبِينٗا
In case you want to replace a wife with another, do not take back anything you may have given to her in the past, even if it were a very large sum. Would you take back (your gift) by resorting to slander and a flagrant injustice