Bechoros Daf 52 בכורות דַף 52

The next Mishnah states: הבכור נוטל פי שנים בנכסי האב – a bechor takes a double share in the father’s estate, but not in the mother’s estate. He does not take a double portion בשבח – in improvements made to the estate after the father’s death, ולא בראוי כבמוחזק – nor does he take a double portion in potential assets as he does in his father’s possessed assets (“potential assets” are those the father stood to inherit or obtain but died before acquiring). A bechor does not receive a double portion of his mother’s estate because the passuk says "ולו משפט הבכורה" – to him is the law of the firstborn, implying משפט הבכורה לאיש – the law of the firstborn to receive a double portion applies to (the estate of) the man (i.e., the father), ואין משפט הבכורה לאשה – but there is no law of firstborn for the estate of a woman (the mother). He does not receive a double portion in שבח – improvements made to the estate after the father’s death, because the passuk says "בכל אשר ימצא לו" – in all that is found with him (i.e., with the father when he died). Similarly, "ראוי" – potential assets were not yet the father’s when he died.

The next Mishnah records four opinions about which land transfers are not returned to their original owners in יובל. Rebbe Meir says: ואלו שאין חוזרין ביובל – and these do not return on Yovel: the bechor’s second share, the property inherited from one’s wife who died, one’s brother property which he received through performing יבום, and a gift. He holds the Torah only requires returning מכר – a sale, not inheritances or gifts. The Torah says, regarding a bechor’s extra portion, "לתת לו פי שנים" – to “give” him a double portion; מתנה קרייה רחמנא – Hashem calls [the extra portion] a “gift.” Rebbe Meir holds ירושת הבעל דאורייתא – a husband’s inheritance of his wife’s assets is a Biblical inheritance, so the property is not returned. The Torah calls a יבם a “bechor,” thus comparing the estate received from his brother to a bechor’s portion, which is like a “gift,” and not returned in יובל. The Chochomim say a gift is returned in יובל, because they darshen the superfluous "תשובו" – you shall return to include a gift. Still, they agree a bechor’s share is not returned, because the expression "פי שנים" – a double portion compares the extra portion to the standard portion, considering it ירושה, which is not returned. [The same applies to a יבם, who is called a “bechor”.] The Gemara explains the last two opinions.

Rebbe Yochanan said: האחין שחלקו לקוחות הן – brothers who divided an estate are considered like purchasers of the properties they received, because we consider them given in exchange for their respective “true” shares (which cannot be identified, because אין ברירה – there is no retroactive determination of their true shares). ומחזירין זה לזה ביובל – Therefore, they return to each other any קרקע they originally received, and it is redivided. Rav Hoshaya challenged this from our Mishnah, which taught that a bechor’s extra portion is not returned. If brothers who divide an estate are לקוחות, the bechor’s received portion should likewise be considered “purchased,” and required to be returned in יובל!? Rebbe Elazar answered that the Mishnah only means אין חוזרין לבטלה – [the properties] do not revert to become nullified. Although the land is returned and redivided, the bechor retains his right to a double portion. Although Rav Sheishess considered it inconceivable that the Tanna who holds the bechor’s share is returned in יובל would hold the bechor loses his extra portion, Rebbe Elazar’s answer is substantiated.