Deuteronomy 21:15

If a man has two wives , the one loved and the other unloved , and both the loved and the unloved have borne him children , and if the firstborn son belongs to the unloved ,

If a man has two wives, and he loves one but not the other, and both bear him sons but the firstborn is the son of the wife he does not love,

If a man have two wives, one beloved, and another hated, and they have born him children, both the beloved and the hated; and if the firstborn son be hers that was hated :