But he shall acknowledge the firstborn, the son of the hated, by giving him a double portion of all that is found with him; for he is the first of his strength, the right of the firstborn is his.
English: “The first of his strength” — the first of his strength, and not the first of her strength.
On the daf / in context: Firstborn status for inheritance follows the father, not the mother. (This differs from the firstborn for the priest, which depends on the opening of the womb.)
Type of Learning
Mi’ut excluding maternal firstborn status.
What Is Learned
The firstborn for inheritance is determined by the father’s first viable offspring, not by the mother’s first birth.