Implied Question: The Gemara here does not ask that if he would throw his coat in the garbage before Shabbos (would it not be a vessel). (Why not?)

Answer: Since this was designated before Shabbos, it is unlike a coat (which is clearly not Muktzah even if thrown in the garbage, as it was previously designated for usage and his opinion that it is unfit is abnormal and therefore insignificant).

Observation: The Gemara is giving this explanation without having to do so, as it does not have to be able to be used for something similar to its previous usage.

Proof: This is as Rav Nachman states earlier that a small piece of earthenware can be carried in the yard because it is fit to be used as the cover of a vessel.

Explanation: This is not specifically referring to a yard, as Rav Nachman and Rava permit a Karmelis and a public domain (respectively, see 124b).

Implied Question: The Beraisa specifically stated, "an old oven." (Why is this only true of an old oven and not a new oven?)

Answer: This is because the broken pieces of a new oven are not fit for anything (Rashi says the pieces of the old oven are hard and fit to be used.)

Question: According to this answer it is difficult to understand why the Beraisa stated, "an old oven" as it is referring to a case where it is the first time it is heated up!

Implied Question: Ravina also could have said that it is according to Rebbi Yosi, who permits later (126b) carrying covers of vessels that have no handles if the vessel is connected to the ground. (Why didn't he say it is according to Rebbi Yosi?)

Answer: Rather, because the teachings of Rebbi Eliezer ben Yaakov are known to be very refined and thorough, he preferred to say it was according to him.

Question #1: This is difficult. How is Rav Asi according to his reasoning? On the contrary, he seems to contradict himself! In our Gemara he says that it is made into a cover for the barrel by just putting it there without doing any other action, and regarding a row of stones he says that you should go out and smooth them before Shabbos! He told them that this type of action was required by Rebbi.

Question #2: Additionally, regarding the row of stones he said that smoothing them down is enough, and later regarding the covers of vessels he says in the name of Rebbi Yochanan that it is only if they are considered vessels!

Answer: It is possible to answer that the cover of the barrel is enough to be placed there, as it is does not require fixing it into a cover and doing a big action to it as is the case with other covers of vessels. The row of stones that have already been smoothed and made square for building can also just have a small action done to them. Accordingly, Rav Asi is based on his reasoning regarding the row of stones, as just as he only requires a small action there, so too he only requires a small action (of placing it on the barrel) here.

Implied Question: Rav Asi earlier (50a) says that one may sit on branches of palm trees on Shabbos even though he did not tie them together before Shabbos. (Shouldn't he require at least a small action before Shabbos as he does here?)

Answer #1: The text there should read "Rav Ashi" not "Rav Asi."

Answer #2: Alternatively, they are more ready to sit on than stones (and therefore do not require a similar action to designate them before Shabbos).

Opinion #1: Rashi explains that the prohibition against making an Ohel is only regarding making a roof, not making walls.

Proof: This is apparent from the incident involving Shmuel in Eiruvin (94a). The Gemara says that the wall separating two yards broke on Shabbos. Rav says one can therefore only carry within four cubits, while Shmuel says that each can carry until the original wall separating the yards (as when Shabbos started this was the status of the yard).

Proof (cont.): Rav's position was not stated by him explicitly, but rather can be derived from the following incident. Shmuel was sitting in a yard when the wall separating this yard from a second yard fell. Shmuel said, take a sheet and put it up between the two yards. Rav turned his face away etc. The Gemara asks, why did Shmuel do this? Doesn't he hold that each can carry until the wall? The Gemara answers, Shmuel did this for modesty (not because of the laws of Shabbos).

Proof (cont.): This implies that the walls of a tent are permitted to be put up on Shabbos. Rav was not bothered by Shmuel's ruling because he held this was a problem of making a tent, but rather because they carried the sheet four cubits in the yard.

Question: This is difficult, as it must be there is a prohibition of making a tent regarding walls as well, as is apparent from the Gemara in Eiruvin (44a). The Gemara asks regarding making the walls of a Sukah, didn't Rabah bar bar Chanah say in the name of Rebbi Yochanan that everyone admits that one cannot make a temporary tent on Shabbos? The Gemara answers, one case is when he is making a third wall of a Sukah while one is where he is making a fourth wall.

Opinion #2: Rather, it appears to Rabeinu Tam that the prohibition against making a tent includes making walls if these walls permit something. This is why it is forbidden to make the third wall of a Sukah, as it is a wall that causes the Sukah to become valid and therefore is considered like making a tent. However, the fourth wall that only adds another wall is not forbidden, since the Sukah was already valid.

Opinion #2 (cont.): The main argument between Rebbi Eliezer and the Rabbanan regarding a tent is referring to the wall of a tent, as a "window stopper" implies a window on a wall.

Proof: If it would be referring to a skylight, it would have used the word "Arubah" as we learn in the Mishnah in Beitzah (35b) that one can throw down fruit (drying on the roof) through an Arubah (skylight).

Opinion #2 (cont.): However, they also argue regarding making a roof, as is apparent later (137b) where this is quoted regarding hanging a sieve which is like a roof.

Proof: This is also implied in Eiruvin (102a). The Gemara says that there were some rams by Rav Huna's house, and during the day they required shade and at night they required air. He went to Rav who told him to wrap up the mat (acting as the roof that provides shade before Shabbos) and leave a Tefach, as during the day it is permitted for him to add onto a temporary tent (he can unwrap it so they can have shade if the roof was already a Tefach wide before Shabbos). This implies it is referring to the addition to the roof of a temporary tent that is an argument between Rebbi Eliezer and the Rabbanan.