Surah Al-Mumtahanah, ayah 11

وَإِن فَاتَكُمۡ شَيۡءٞ مِّنۡ أَزۡوَٰجِكُمۡ إِلَى ٱلۡكُفَّارِ فَعَاقَبۡتُمۡ فَـَٔاتُواْ ٱلَّذِينَ ذَهَبَتۡ أَزۡوَٰجُهُم مِّثۡلَ مَآ أَنفَقُواْۚ وَٱتَّقُواْ ٱللَّهَ ٱلَّذِيٓ أَنتُم بِهِۦ مُؤۡمِنُونَ ١١

Wa in fātakum shay'um min azwājikum ilal-kuffāri fa'āqabtum fa'ātul-ladhīna dhahabat azwājuhum mithla mā anfaqū wattaqullāhal-ladhī antum bihī mu'minūn

And if you have lost any of your wives to the disbelievers and you subsequently obtain [something],¹⁶⁷⁸ then give those whose wives have gone the equivalent of what they had spent. And fear Allāh, in whom you are believers.