Deuteronomy 21:10-11

Laws Concerning Wives

21:10 When you go out to do battle with your enemies and the Lord your God allows you to prevail and you take prisoners, 21:11 if you should see among them an attractive woman whom you wish to take as a wife,

Deuteronomy 21:14

21:14 If you are not pleased with her, then you must let her go where she pleases. You cannot in any case sell her; you must not take advantage of her, since you have already humiliated her.