Deuteronomy 21:10-13

When you go out to war against other nations, and the Lord your God gives them up into your hands and you take them as prisoners; If among the prisoners you see a beautiful woman and it is your desire to make her your wife; Then take her back to your house; and let her hair and her nails be cut; And let her take off the dress in which she was made prisoner and go on living in your house and weeping for her father and mother for a full month: and after that you may go in to her and be her husband and she will be your wife.