Explanation (Rashbam): He writes this once at the beginning of the document, and once at the end, like it says that he must repeat the content of the document in the last line.

Question: We do not learn from the last line. (This is an enactment, lest witnesses leave a blank line before signing, and the bearer will add words after they signed.) If [like the Rashbam explained] we learn from it, for due to [Aknei v'Kanina Minei] we do not obligate writing "from today [and after I die]"!

Question: If so, what was the need for the enactment of Usha, that if a woman sold her Nichsei Melug in her husband's lifetime, and she died, that her sale has no effect (below, 139b)?

Answer #1: [It is needed for when] he wrote to her "I have no claim to the Peros of your property, and not to the Peros of your Peros";

However, he did not write "[I have no claim] to your property", for if so her sale stands, like it says in Kesuvos (83a).

Answer #2: There, Kinyan Peros of the husband is only mid'Rabanan, and it is not like Kinyan ha'Guf. Therefore, Takanas Usha was needed.

Explanation (Rivam): It returns to the heirs of the son, and the buyer cannot say "your father sold, and you take [what he sold]?!", like we say below (159a).

Implied question: Here, the reason below (why the buyer cannot say so) does not apply, i.e. because the [son's] son can say "I come based on my grandfather's rights." If so (that reason applied), the father's brothers would take their share, since [the son's son] does not come based on his father's rights, rather, based on his grandfather's rights!

Answer: [Here,] the reason it returns to the son's heirs is because when the son died, the property fell to his son. When his grandfather died, the son inherited in the grave automatically, and afterwards the son of the son inherited.

Question: It says below "one might have thought that the father, even regarding his son, Nafshei (he himself) has precedence", and the buyer cannot take when the father dies;

If the sale is void, [the property] does not return to the father, rather, to the son's heirs!

Answer: The son's son is properly called "Nafshei" in contrast to the buyer.

Implied question: Why is this unlike "my property is to you, and after you to Ploni, and after Ploni to Almoni"? [There], if the second (Ploni) dies in the life of the first [recipient], the property returns to the first's heirs;

We do not say that since he was Makneh the Guf to the third (Almoni) at the end, it is as if the property falls to him when the second died!

Answer: [The giver] was not Makneh anything to [the third] until after the second acquired;

Implied question: According to Rav Anan, who said above (125b) "to my heirs", and not to the heirs of my heirs, for according to him, if he said "my property is to you, and after you to Ploni", if the second dies in the first's lifetime, it does not return to the second's heirs [here, it should not go to the grandson]!

Answer: Here is different. [There], the first has more [rights] in the property than the father [does here], for there, if the first sold, all the property is sold, for the Halachah follows R. Shimon ben Gamliel, who says that the second receives only what the first left over;

However, here the father can sell only [rights to eat the Peros] until he dies. Therefore it returns to the son's heirs, and there it returns to the first's heirs.

Explanation #1 (Rashbam): He brings because this is called "your land." He does not recite, for this is not called "the land that You gave to me."

Objection: If it is called "your land", it is called also "the land that You gave to me"!

Explanation #2: (Really, it is not called "your land.") Chachamim enacted to bring, due to Kinyan Peros (even though it is not like Kinyan ha'Guf);

They did not enact to recite, for we said above (82a) that it looks like Sheker (for it is not really his land), or lest people come to [think that they are really Bikurim, and] exempt them from Terumah and Ma'aser.

Explanation #1 (Rashbam): [We ask that] this is difficult for R. Yochanan, who says that Kinyan Peros is like Kinyan ha'Guf. [The Gemara] answers that Tana'im argue about whether or not Kinyan Peros is like Kinyan ha'Guf.

Objection #1: We find many Tana'im who argue about Kinyan Peros more explicitly than these, regarding one who sold his Eved [Kena'ani] Al Menas (on condition) that he will [still] serve the seller for 30 days (above, 50a)!

Objection #2: According to the Rashbam, the text says only 'Tana'im argue about "after you"'!

Explanation #2: We ask against Reish Lakish, who answered that "after you" is different. We ask as follows;

Granted, if you will say that "after you" is not different, rather, [the Beraisa] that says that [the property] returns to the first's heirs, because he holds that Kinyan Peros is like Kinyan ha'Guf, like R. Yochanan...

And [the Beraisa that] says that it returns to the giver's heirs, it holds [that Kinyan Peros is] unlike Kinyan ha'Guf, like Reish Lakish, this is fine, for we find many Tana'im who argue about this;

However, if you will say that the Beraisa says that it returns to the first's heirs also holds that normally, [Kinyan Peros is] unlike Kinyan ha'Guf, and the reason here is because that "after you" is different, [this is difficult, for] a Beraisa says that it returns to the giver's heirs!

It is unreasonable to say that [this Beraisa] holds "after you" has no effect, for we do not find that Tana'im argue about this!

Explanation #2 (cont.): We answer that Tana'im argue about "after you." I.e. really, the first [Beraisa] is even like Reish Lakish, and Tana'im argue also about "after you", like we bring that Rebbi and R. Shimon ben Gamliel argue about "after you";

Rebbi holds that "after you" has no effect. He was Makneh to him only Peros. R. Shimon ben Gamliel holds that "after you" is different.

Conclusion: Now, all of them (Rebbi and R. Shimon ben Gamliel) hold like Reish Lakish, whom the Halachah follows.

Note: Maharsha asks, why do we say that Rebbi and R. Shimon ben Gamliel argue about "after you"? We do not find that Tana'im argue about this. We should say that they argue about Kinyan Peros! The following comment answers this.

Explanation: We properly bring [from this Beraisa] that Tana'im argue about "after you", even according to R. Yochanan, and not about whether or not Kinyan Peros is like Kinyan ha'Guf;

Source: R. Shimon ben Gamliel's reason is that the latter gets only what the first left over. You are forced to say that this is because he said "after you";

If it were due only to Kinyan Peros, obviously he cannot sell, just like the father (who gave the Guf to his son and kept the Peros), who cannot sell! (It seems that this comment is attributed to Maharsha because he was the first to cite it.)