Quran 60:11 — The Test (Al-Mumtahanah)

If any of your wives join the enemies' camp, and you are forced to fight, you shall force the enemy to compensate the men who lost their wives, by giving them what they spent on their wives. You shall reverence GOD, in whom you believe.

[60:10] O you who believe, when believing women (abandon the enemy and) ask for asylum with you, you shall test them. GOD is fully aware of their belief. Once you establish that they are believers, you shall not return them to the disbelievers. They are not lawful to remain married to them, nor shall the disbelievers be allowed to marry them. Give back the dowries that the disbelievers have paid. You commit no error by marrying them, so long as you pay them their due dowries. Do not keep disbelieving wives (if they wish to join the enemy). You may ask them for the dowry you had paid, and they may ask for what they paid. This is GOD's rule; He rules among you. GOD is Omniscient, Most Wise.

[60:12] O you prophet, when the believing women (who abandoned the disbelievers) to seek asylum with you pledge to you that they will not set up any idols besides GOD, nor steal, nor commit adultery, nor kill their children, nor fabricate any falsehood, nor disobey your righteous orders, you shall accept their pledge, and pray to GOD to forgive them. GOD is Forgiver, Most Merciful.