Explanation: We infer that the Mishnah means "or, he plasters." Only loose earth requires distance and plaster.

We answer that the same applies if it is not loose earth. The Tana needed to teach about loose earth...

Alternate text: Some texts do not have this inference. Rather, we answer that loose earth is different. We ask "what was the Havah Amina of the one who tried to bring a proof from here?"

Rebuttal: This is unreasonable. How did we want to resolve that the Mishnah means "and he plasters"?

We can ask about R. Yehudah's teaching itself, whether or not he requires both, since now we hold that it makes no difference whether or not it is loose earth!

Explanation #1 (Rashi): They (rocks) break the pot. Therefore, it is not normal to insulate in them.

Question: Still we can ask that it is not normal to insulate in tufts of wool, like we asked above!

Answer #1: Above, we wanted to say that it is not normal to insulate in rocks, because the heat leaves between the rocks, and it does not stay [hot]. Even so, sometimes one insulates in them;

Therefore, we ask properly from tufts of wool. It was taught because sometimes one insulates in them;

However, here we say that it is not normal to insulate in [rocks] at all, because they break the pot. Since it is not common at all, the Tana was not concerned to teach it.

Answer #2: Also, we can explain that since it is not common at all, it is permitted to insulate in them, for Chachamim did not decree about something that is not common.

Support: Our custom is that we insulate in rocks from which fire exudes, called Kailosh (flint stones).

Question: In any case, Rashi's question is difficult. Everywhere, "Shituch" is an expression of rust!

In Bava Metzi'a (26a) it says "it is exceedingly Shasich", and in Shabbos (102b) it says "since Mishtachi, they do not do so"!

In Ta'anis (8a) it says "if you see a generation that Shamayim is Mishtachin on it like copper..."!

Explanation #2 (R. Tam): Mishtachi means that their heat ruins the food.

Explanation #3 (Ri, from R. Chananel): One must distance them because Mishtachei, i.e. they ruin the land, corrode it and loosen the earth, like we say below (19b) regarding seeds.

It is not due to heat, for they do not add any heat. (They were not taught regarding insulation, for there is no reason to forbid.)

Pesak: One may insulate in them, even according to Seforim (Explanations #1,2) that say [that the Gemara gives] the reason why rocks were not taught there [regarding insulation];

We can say that the reason they were not taught there is due to the reason here that one must distance them. It is not due to heat, rather, because they are Mishtachei. (Therefore, there is no Isur to insulate in them, just it is not normal to do so.)

Support: R. Mordechai brought a proof from the Yerushalmi, which says "there, it says that rocks heat. Here, it says that rocks do not heat!"

Citation (Yerushalmi - R. Yosi): In both places, rocks do not heat. Rather, it is because they loosen the earth, and harm the ground of the wall.

Implied question: It says in Shabbos (38b) that one may not insulate an egg [even if it is cold] in sand or dust of the road!

Answer: There, the sand was heated in the sun, just like dust of the road.

Explanation: This refers to a lone vine that took root in the ground. He bends the vine in its middle and covers it in the ground, and it takes root there.

It says that it is permitted to seed on its sides, even though it is not three Tefachim away, and it nurtures with the vine under the ground;

Since above the ground there is no mixing, it is permitted, like is proven in Eruvin (93a) and Kil'ayim (4:4) this one is Somech to the fence on this side, and this one is Somech to the fence on the other side.

Question: What is the case of seeding the sides?

If he distanced three Tefachim from the sides, even on top of it is permitted! If he did not distance, also from the sides is forbidden!

Answer (Ri): We discuss when he seeded the sides three Tefachim away from where the vine leaves the ground on every side, so there is no mixing above the ground;

In any case one may not seed on top of it, for the roots enter the vine, and this is like grafting vegetation onto a tree, which is forbidden.

Question: Why did he discuss a vine? Even other trees are forbidden [on top]!

Answer (Ri): Other trees are hard, so one may seed on top, in line with the root. We are not concerned lest the root of the seed enter the tree, which is hard;

However, a vine is soft, so we are concerned.

Support: The Ri found this answer in the Yerushalmi, in the Gemara on this Mishnah.

Question: Granted, if we discuss one who urinates, even though it taught an irrigation channel, he taught also this. One might have thought that for modesty, it is permitted [to urinate near his neighbor's wall];

However, if we discuss pouring [urine from a urinal], what is the Chidush? The Tana taught an irrigation channel! For this reason, we said above (19a) that he did not teach [wet] sand (because he already taught an irrigation channel)!

Answer: Sand is different, for it is constantly by the wall. Urine is absorbed immediately.

Implied question: Why can't we answer that Rabah bar bar Chanah discusses rocky land?

Answer #1: If so, he should have specified explicitly.

Answer #2: He expounds a verse. This shows that he does not distinguish.

Explanation: We bring this teaching here due to what we ask below, that since Zera'im harm a wall, he will remove them.

Explanation: Rivam explained the laws of a window based on the Mishnayos;

If the window was made for use, its Shi'ur to bring Tum'ah (Tum'as Ohel) is a square Tefach;

When it is diminished from a Tefach, even Mashehu, it does not bring Tum'ah.

If the window was made for light, and it is man-made, its Shi'ur is a big drill of the chamber (needed for upkeep of the Mikdash), which is like the size of an Italian Pundiyon, which is a Sela of Niron.

This is bigger than a Stam Sela, for a Stam Sela is less than a Stam drill, and all the more so it is less than a big drill, like we say in Bechoros (37b);

The window made for light is not diminished through a blockage of Mashehu, since it initially had a Shi'ur. Rather, [it brings Tum'ah] until it is diminished so it does not have [an opening of] the height of two fingers and a width of a thumb.

If a window for light is not man-made, rather, it came about by itself, e.g. water or Sheratzim bored a hole, its Shi'ur is the size of a [big] fist;

If one intended to use it, its Shi'ur is a square Tefach. If one intended for light, its Shi'ur is the size of a drill;

It explains there (Bechoros 37b) that the fist is of Ben Avati'ach. R. Yosi says that it was the size of a normal person's head.

If it is not made for light, and not for use, only for air, and to [look outside and] guard gardens and orchards, its Shi'ur is the size of an average drill.

Explanation: Now we are thinking that it mentioned specifically a wafer, for it has two attributes:

It is not a good sealing, since it is soft, and prone to fall. Also, one is not Mevatel it there.

Support: This is why we ask "even if it is thick", and it will stay there, since he is not Mevatel it, it does not diminish.

Explanation: Even if he would be Mevatel it, it does not block [Tum'ah], because it is Mekabel Tum'ah!

Question: If he is Mevatel it, it is not Mekabel Tum'ah any more, and it is Tahor, like is proven in Chulin (129a)!

[A Beraisa] says that Se'or (sourdough) that was designated to sit on, it is Batel. [Rav Masnah taught that] if one made a roof from vegetation, the vegetation becomes Tahor.

Inference: Once he is Mevatel it, it is not Mekabel Tum'ah!

Answer: There we discuss when he made a Shinuy Ma'aseh (changed it through an action).

Source: We say in Shabbos (52b) that all Kelim descend to receive Tum'ah through intent, and they leave Tum'ah only through Shinuy Ma'aseh.

Similarly, food requires Shinuy Ma'aseh;

Even handles of foods, it is proven in Sukah (14a) that there is a Tana who holds that they require Shinuy Ma'aseh [to lose their Tum'ah].

Observation: We could have answered that the case is, it is less than a k'Beitzah;

In Ohalos (13:5), we list less than a k'Beitzah of food among matters that diminished the Tefach.

Explanation (R. Chananel): [It was kneaded with fruit juice, e.g. oil].

Rejection: He was not precise. Oil is Machshir (if it is put on a food, the food is Mekabel Tum'ah), like is clear from Shabbos (5b and 144a) that oil is considered a liquid!

Rather, only the Mohel (liquid) that exudes [from the olives] at the beginning [is not Machshir].

Question: Still, it is proper for his animal through crushing, like is proven in Shabbos (155b);

Citation (155b): We can learn from the following. We crush straw... This shows that one may toil with food [to prepare it for animals]! We answer that the straw is spoiled

Answer: Here we discuss when it is so spoiled that through any fixing, it will not be proper [for animals].

Suggestion: The reason is because in the end, he will take the barrel or box. Therefore, we require that the figs and straw can stand by themselves.

Rejection: If so, what was the question "if there is straw, he sees it!"? The Gemara wanted to prove from this even what will be taken is a Chatzitzah;

We can challenge the one who brought this proof! Why must it be able to stand by itself?

Explanation (Ri): Rather, this is the law. Anything that blocks, it must be able to stand by itself;

Before this Mishnah, it is taught in Ohalos (6:2) that if people who bury a Mes were passing through an Achsadra (a house without four walls), and one of them closed the door and supported it with a key...

If the door can stand by itself, it is Tahor. If not, it is Tamei, and similarly regarding a barrel of figs and box of straw that are placed in the window.

Inference: It is all due to one reason, because it is a haphazard closure, since it cannot stand by itself;

Alternatively, we require that a Chatzitzah stand through something that is not Mekabel Tum'ah.

Disclaimer: However, in the Perush of the Mishnayos, the Ri found one who explains that we discuss even with a key that is not Mekabel Tum'ah;

It is Metamei because it is not considered an Ohel to block Tum'ah, since it stands through a Kli, even though it is not Mekabel Tum'ah.

R. Eliezer argues in the Tosefta, and says that it is Tahor, since the key is not Mekabel Tum'ah.

Explanation: They argue like they argue in Maseches Ohalos about a row of rocks on Kelim, even on Kelim of dung, stone or earth;

According to R. Eliezer, it becomes an Ohel to be Metaher. According to Rabanan, it is an Ohel only when it is on rocks.