Deuteronomy 21:17
but he shall acknowledge as firstborn the son of the hated, by giving him a double portion of all that is found with him; for he is the firstfruits of his vigour: the right of the firstborn is his.but he shall acknowledge as firstborn the son of the hated, by giving him a double portion of all that is found with him; for he is the firstfruits of his vigour: the right of the firstborn is his.