Mishnayos Bechoros Perek 8 Mishnah 9

ולא בנכסי האם – the usufruct property (i.e., the wife’s personal property from which her husband is entitled to benefit – brought into the marriage from her father’s home and that is not included in her marriage contract, and property that she inherits or receives as a gift after her marriage) of the mother, as it is written (Deuteronomy 21:17): “since he is the first fruit of his vigor, the birthright is his due,” implying that it refers to that which is his (i.e., the father’s), that is to say, with his property, “the birthright is his due,” but not the property of his wife.

ואינו נוטל פי שים בשבח – if the property [of the father] grew in value after the death of the father prior to their dividing it, the first born does not take a double portion of the increased value/amelioration. But rather, they assess the property, what it was worth at the time of the death of the father and the first-born [son] takes a double portion of them alone, as it states (Deuteronomy 21:17): “and allot to him a double portion of all he possesses,” of what belonged to the father at the time of [his] death.

ולא בראוי (what is coming due to the estate [as he does of what is held in possession]) – in the property, for their father did not hold in possession at the time of his death, but other than what was appropriate to fall to him in inheritance, but what fell to them after a time, the first-born does not take from them a double portion.

ולא האשה בכתובתה – in the growth that accrued . But if the property [value] is not equivalent at the time of the death of her husband in order to the measure [of what is written] in her Ketubah, but afterwards it increased [in value], she does not take for her Ketubah settlement other than what they were worth [at the time of his death], and even though in general, the creditor collects the increase in value, this is one of the leniencies of the Ketubah that they taught here. And she does not take what is coming due to the estate as she does of what is held in possession.

ולא הבנות – [the daughters do not] take maintenance/alimentation after the death of their father according to the conditions of her (i.e., the wife’s) Ketubah (see Tractate Ketubot, Chapter 4, Mishnah 11), but the female children, they will be yours, but from me they may dwell in my house and are supported from my property. Not from the increase in value of the property nor from that which is appropriate to come after death. Since the maintenance of the daughters is from the conditions of the Ketubah, they are like the Ketubah itself.

ולא היבם – [the levir] who takes a portion of the [property] of the dead when he performs levirate marriage with his wife, he does not take the portion of his brother, neither from the increase [in value] nor form that which is coming due to the estate [over time]. What is the reason? The All-Merciful calls him “the first born (Deuteronomy 25:6): “The first son that she bears shall be accounted to the dead brother,” like the first-born son; just as the first-born does not take from the increase nor that which is appropriate to come [to him], so too the levir does not take neither the increase in value nor what is appropriate to come (i.e., what is expected to accrue to the estate).

וכולן אינן נוטלין בשבח – He teaches this again [in the Mishnah] to include increase that comes of its own accord/automatically, as for example, grain that was ruined when his father died and now it made ears of corn, or dates in the budding stage and they now became large dates. For if the Mishnah had only taught the first clause, I would think that the firstborn does not take a double-portion of the increase in value, that they words refer to the increase that his brother was busy with as for example the manuring of the fields and the crushing of the earth and the hoeing.

ולא בראוי כבמוחזק – to include [as well] if the father of their father was alive at the time of the death of their father, that the property would be appropriate to them [via inheritance] when he would die, even though that certainly, it would eventually fall to them, and even if he has another son, these would take the portion of their father, for I might think that it is like what is held in possession. Hence, this is not the case. For if only from the first clause of the Mishnah, I might think that what is appropriate according to what is taught in the first clause, the first born does not take, as for example, when the property of the brother of their father who did not have children fell to them at the time of the death of their father, it is not appropriate other than from doubt, for perhaps he will not have issue.