Question: Why did it teach "but if they built houses"? It should distinguish in this very case of Muchkeres or rented!

When [does the Bechor receives two portions]? When it is not lacking food. However, if it lacks food, the Bechor does not receive two portions.

Answer: One might have thought that in this very case of Muchkeres or rented, only when it lacks food, the Bechor does not receive two portions, for this is absolute Ra'uy, for the Shevach is not on the cow's body itself;

However, if they built houses and planted vineyards, the Shevach is on the land. I would say that this is not Ra'uy, and the Bechor receives two portions. The Beraisa teaches that this is not so.

Explanation #1 (Ri): This makes a difference if the orphans are minors. The Bechor can say "I will not take a double portion, and the land will remain in front of the orphans, and [the creditor] will not take from them, for we collect from [minor] orphans only if Ribis is accumulating [to a Nochri creditor - Bava Kama 39a].

Below, we learn from "Lases Lo" that the Bechor can waive his Bechorah, because it did not yet come to his hand.

[He can waive his Bechorah] even without a Kinyan, like it connotes below. It says that he pardoned it in all the property. Since he pardoned in this, he pardoned in this.

Distinction: However, his Pashut portion he cannot pardon and remove himself from it through mere words, only through a Kinyan.

Explanation #2 (R. Tam): If when the document came against the Bechor himself and not against the brothers, he said "I will not take and I will not give", he may. The creditor loses (if the Bechor does not have enough property to pay the entire debt), and he has no claim against the [other] orphans. He has no case against them;

This is unlike the Reisha, which discusses when a loan document came against all of them.

Question #1: In the entire Gemara we say that the Halachah does not follow Rebbi against his colleagues. Why is [R. Chiya] unsure here?

Question #2: Rav Nachman himself says [here] that the Halachah follows Rebbi even against his colleagues. We hold like Rav Nachman in monetary laws, and we hold that the Halachah does not follow Rebbi against his colleagues!

Answer (R. Tam): Only here [R. Chiya] is unsure, but not elsewhere, and also Rav Nachman [rules like Rebbi even against his colleagues only here].

Question #1: Rav Nachman said that one may do like Rebbi. Since he holds that here, the Halachah follows Rebbi against his colleagues, why does he say "one may"? He should have said "one must do like Rebbi"!

Question #2: It says that Rava holds that we lean. I.e. the matter leans to do like Rabanan l'Chatchilah. In the entire Gemara, we say "leans" only about the side that the Halachah follows!

This is like it says in Kesuvos (84b) regarding "the Halachah follows R. Akiva against his colleague." One holds that this means that the Halachah follows him, and one holds that we lean [to rule like him];

Here, the Halachah was said only regarding Rebbi, and not Rabanan! (I.e. do not say that Rava means that the Halachah leans towards Rabanan.)

Answer (Ri): He is unsure if they explicitly ruled that the Halachah follows Rebbi against his colleague, but not against his colleagues. (Maharsha - they explicitly ruled that the Halachah follows Rebbi against his colleague. Did they also rule that the Halachah does not follow him against his colleagues, or is there no general rule about this, and the Halachah could follow Rebbi?)

Explanation: He establishes this like Rabanan, and there is a loan document.

Explanation: Above, regarding "if they inherited a loan document, the Bechor receives two portions", the Rashbam explained that the document is the Guf (the property itself), and the loan is the Shevach.

Rebuttal: If so, why do Rabanan say that the Bechor does not receive two portions? Since they divide the documents, and he receives two portions of documents, for they are the Guf, he gets also two portions in the Shevach that comes afterwards, i.e. the loan!

Obviously, after they divide, all the Shevach that comes to his portion is his!

Explanation #1: Below (125a), R. Tam explained that Rav Nachman himself holds that whether they collected land or coins, [the Bechor] has [a double portion].

Support: It is fine that it says here that Neharde'ei hold like they taught elsewhere, for also Ameimar said Stam that he receives two portions in a loan, whether they collected land or coins.

Explanation #2: The Rashbam explained below that Rav Nachman himself holds that whether they collected land or coins, [the Bechor] does not have [a double portion].

Rejection: If so, we cannot say that Neharde'ei hold like they taught elsewhere!

Explanation #1 (Rashbam): Since he gave coins and got back coins [he is considered Muchzak].

Rebuttal: In Bava Kama (43a), Rabah and Rav Nachman establish R. Akiva's law, that a husband does not inherit damages due to his wife, only regarding a divorcee. The Gemara asked that Rabah should establish it when they collected coins, and Rav Nachman should establish it when they collected land, for then it is Ra'uy;

Why did it say [that Rav Nachman should establish it when they collected] land? Also if they collected coins, it is Ra'uy!

Source: This that [Rav Nachman] said here that if they collected coins, the Bechor receives [two portions] and it is Muchzak, this is because he gave coins and got back coins. There, regarding damages, he did not give coins. Rav Nachman should agree that also if they collected coins, it is Ra'uy!

Suggestion: We ask that Rabah should establish it when they collected coins, and Rav Nachman should establish it even when they collected land.

Rejection: Also Rabah could establish it when they collected land or coins, for so he holds below (175b)!

Rather, because according to Rav Nachman we could mention only one, i.e. they collected land, it mentions also according to Rabah [only] one.

Explanation #2: Rather, the reason why Rav Nachman said here that if they collected coins, the Bechor receives [two portions] is because it is normal for creditors to pay coins for their debts, and not land, and he is Muchzak when they collected coins, is because people rely on them;

However, it is not normal to pay land for debts. People do not rely on it, so he is not Muchzak.