Deuteronomy 21:10-14

When you go out to do battle with your enemies and the LORD your God allows you to prevail and you take prisoners, if you should see among them an attractive woman whom you wish to take as a wife, you may bring her back to your house. She must shave her head, trim her nails, discard the clothing she was wearing when captured, and stay in your house, lamenting for her father and mother for a full month. After that you may have sexual relations with her and become her husband and she your wife. 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.