Deuteronomy 21:15-17 - The Right Of The Firstborn

¹⁵ When there shall be to a man two wives, the one loved and the one hated, and they bare sons to him, the loved and the hated, and the first-born son was to her being hated: ¹⁶ And it was in the day of his causing his sons to inherit what shall be to him, he shall, not be able to make the son of the loved first-born before the son of the hated, the first-born: ¹⁷ But he shall acknowledge the son of the hated, the first-born, to give to him the portion of two in all that shall be found to him; for he is the beginning of his strength; to him is the judgment of the first-born.