Deuteronomy 21:13-15

New Catholic Bible

¹³ and have her throw out the clothes she was wearing when she was taken captive. She is to live in your house for a full month and mourn her father and her mother. Then you may go to her and be her husband and she will be your wife. ¹⁴ If you are not pleased with her, you are to let her go wherever she wishes. You are not to sell her or treat her like a slave, for you have already humbled her.

¹⁵ Law of the Firstborn.^[a] If a man has two wives, and he loves one and dislikes the other, and they both bear him children, both the one who is loved and the one who is disliked, and the son of the one who is disliked is the firstborn,