Deuteronomy 21:10-13

10When thou goest forth to battle against thine enemies, and Jehovah thy God delivereth them into thy hands, and thou carriest them away captive, 11and seest among the captives a beautiful woman, and thou hast a desire unto her, and wouldest take her to thee to wife; 12then thou shalt bring her home to thy house; and she shall shave her head, and pare her nails; 13and she shall put the raiment of her captivity from off her, and shall remain in thy house, and bewail her father and her mother a full month: and after that thou shalt go in unto her, and be her husband, and she shall be thy wife.