60:10 Believers, when believing women come to you as emigrants, test them. Allah best knows their belief. If you find them to be believers do not return them to the unbelievers; they are not permitted to the unbelievers, nor are the unbelievers permitted to them. But give back to the unbelievers what they have spent, and there is no fault in you to marry such women, provided you give them their dowries. Do not hold on to the ties with unbelieving women, ask what you have spent and let them ask what they have spent. Such is the Judgement of Allah; He judges between you; and Allah is the Knower, and the Wise.
60:11 If any of your wives desert you to be with the unbelievers and you retaliate, give those whose wives who have deserted the equivalent of what they have spent. And fear Allah in whom you believe.