Explanation #1 (Rashbam): If Stam he acquires the airspace above the roof, which is 10 [Tefachim] from the roof, and also the building below he acquires, does he not acquire the roof in between?!

It is unreasonable that there is an interruption in his Kinyan.

Explanation: This forced the Rashbam to explain that "even though he wrote to him the depth and height" in our Mishnah [below on this Amud] does not refer to the roof (the Reisha, 61a, says that he does not acquire it);

If it referred to the roof, if so, even if Stam he does not acquire, he could ask as follows. When he wrote the depth and height, he acquires the building below the roof, and the airspace, and he does not acquire the roof in the middle! (Why is the question only if Stam he acquires?)

He answers that since [the wall] is 10 Tefachim tall, the roof is important, and he does not acquire it. However, he acquires the airspace above.

Support: The Rashbam explained like this, and so we must explain.

Suggestion: Perhaps since he does not acquire the roof, also the airspace he does not acquire, so there will be no interruption in his Kinyan!

Rejection: It is proven below that if he said Stam, he acquires the height. Even if the roof is 10 tall, he acquires the airspace above until the sky, even though he did not acquire the roof;

We ask from Rav Papa, who said that if he wanted to build on top, he builds. We are thinking that he discusses literally on top of it, in the airspace above the roof.

He builds on pillars [resting on the ground] so it will not weigh down on the wall.

If you will say that he does not acquire, why do we need Al Menas? I.e. even without Al Menas, he can build an Aliyah in the airspace above the roof!

And if [you will say that] also when he said Stam he acquires, when the roof is 10 tall he does not acquire the airspace above, for if also Stam he acquires, it is difficult, why do we need Al Menas?

Question: This is difficult for the Rashbam's Perush. The Makshan asks based on this reason, that there should not be an interruption in his Kinyan, and the Gemara is not concerned for [his reason].

Explanation #2 (Ri): ["Even though he wrote to him the depth and height"] refers [also] to the Reisha (61a) "but not the roof", like I explained above (63b DH Ahani);

The Gemara asks as follows. Granted, if you will say that Stam he does not acquire the depth and height, since with exertion (writing these extra words) he wants [the buyer] to acquire the height, this is fine;

Since the roof is 10 tall he does not acquire the roof, for through a small matter the Kinyan is Batel, for the roof is not Batel to the house;

However, if you will say that Stam he acquires, since it is so easy to acquire, if so, even a roof with a 10 Tefachim wall, he should acquire, since one sells so generously, that even Stam he acquires the height!

Explanation #2 (cont.): He answers that really, Stam he acquires the height. Even so, Stam he does not sell a roof 10 tall, unless he wrote the depth and height, since it is important.

Note: This is like it says above (63b), that "even though he wrote..." really means "even if he did not write [the depth and height], it is as if he wrote [this] to acquire the depth and height, but he acquires Bor and Dus only if he truly wrote it."

Objection #1 (R. Tam): The Rashbam explained that "Diyuta" is a roof with a 10 Tefachim wall. This is difficult, for in Shabbos it is proven that Diyuta is a row!

Citation (96a - Mishnah): If two ledges are opposite each other in Reshus ha'Rabim, one who passes or throws from one to the other is exempt. If both were in one Diyuta...

Inference: [Diyuta] is one row. They are not opposite each other.

Objection #2: [The Rashbam] explained Rav Papa's teaching that if it falls, he rebuilds it. The words of Rav Papa do not connote like this. He said "if he wants to build an Aliyah on top, he builds!"

Inference: He builds on the roof itself!

Objection #3: He is forced to make a difficult distinction between this Diyuta and the one in Bava Metzi'a [117a, regarding rebuilding it - see Tosfos 63b DH she'Im].

Explanation #3 (R. Tam): The top Diyuta is the top row of bricks on the wall, which the roof rests on;

We asked "for what Halachah did he say "the top row is mine"? He cannot remove it if he wants, for he sold the entire house. In what sense is it his?

Rav Zevid explains that if he wants to extend ledges, he may extend, i.e. on the top row, even though it weighs down on the house.

Rav Papa explains that if he wants to build an Aliyah on top, he builds on pillars, so he does not weigh down on the house. However, he may not weigh down on the house.

We ask according to Rav Papa, why does it say "this teaches that"? Even though he may build an Aliyah on top, we conclude that Stam, he does not acquire the depth and height;

If so, since his words do not help to retain [rights] in the house itself, and he may not weigh down [on it], why does it say "this teaches that"?

Obviously, his words help for if it falls, that he may rebuild it. From our Mishnah we learn that his extra words help.

Distinction: For Rav Zevid, "this teaches that" is fine. He retain [rights] in the house itself.

Explanation #3 (cont.): According to the conclusion, that Stam he does not acquire the depth and height, we conclude that according to Rav Papa, [it teaches that] if it falls, he may rebuild it.

This does not refer to the Aliyah [falling]. Rather, if the house falls, and the buyer does not want to rebuild it, the owner of the Aliyah may build the house and Aliyah on pillars, like initially, and he dwells in it until [the buyer] pays his expenses.

Question: What difference does it make that the house is built under the Aliyah, since the Aliyah is not built on the walls of the house, rather, on pillars fixed in the Chatzer?

Also without the house, he can do so!

Answer #1 (R. Tam): This is so he will not constantly fear lest the Aliyah collapse and fall to the ground.

Answer #2: Also, it affects that the wind will not blow under the Aliyah and cool it.

Question #1 (against R. Tam's Perush): In Sanhedrin (31a), it says that if one witness said [that Reuven borrowed from Shimon] on the top Diyuta, and one said on the bottom Diyuta, a case occurred and Rebbi joined the testimonies;

If Diyuta is a row of the wall, how did he lend to his friend on a row of the wall?!

Rather, this connotes that it is the roof.

Objection #2 - Citation (Eruvin 88a - Mishnah): If there are two Diyutos opposite each other, and some of them made an Ukah (a pit for wastewater)...

This does not connote at all that it is a row of a wall. Rather, it is a roof.

Explanation: This is when there is the reason of [the buyer did not want] trampling [on his property], and [the seller wants to be able to access what he kept without] flying;

However, when this does not apply, e.g. regarding trees, no (we do not follow the buyer's intent).