15If a man has two wives, the one loved and the one hated, and they bear sons to him, the loved and the hated, then it shall be that the firstborn son belongs to the hated.16And it shall be on the day that he causes his sons to inherit what he has, he shall not be able to treat the son of the loved as firstborn before the son of the hated, the firstborn.17For he shall acknowledge the firstborn son of the hated by giving him a double portion of all that is found with him, because he is the first of his strength; the legal right of the birthright belongs to him.