Question: Perhaps R. Eliezer and R. Yehudah do not argue with the first Tana (i.e. Chachamim of R. Yochanan ben Nuri), rather, they come to explain his words!

We find like this in Sanhedrin (21a) regarding "Lo Yarbeh Lo Nashim", and in the Mishnah in Bava Basra (28a).

Answer (Ri): You are forced to say that R. Eliezer does not explain the first Tana's words, rather, he argues with him, for the first Tana addresses R. Yochanan ben Nuri, who says that he has 2000 Amos in every direction, and he is not in their middle (i.e. that he has only 1000 Amos in every direction). The same applies to the four Amos of the first Tana.

Question: If so, what was the question "R. Yehudah says just like the first Tana!", since the first Tana addresses R. Yochanan ben Nuri, and [the first Tana holds that] he has four Amos in every direction!

Answer: The Makshan holds that even though the 2000 of R. Yochanan ben Nuri are in every direction, and they are 4000 Amos by 4000 Amos, the four Amos of the first Tana are four Amos in all;

This is like carrying four Amos in Reshus ha'Rabim, which is four Amos in any direction that he wants, like R. Yehudah says. Therefore, we ask "he is just like the first Tana!"

Alternative text: R. Chananel's text says "Chachamim are just like the first Tana!", i.e. the first Tana of our Perek. If Nochrim took someone out [of his city], he has only four Amos;

Even though these are not the same matter, still he asks that Chachamim who argue with R. Yochanan ben Nuri should not have mentioned four Amos, rather, [said] just "he does not have 2000 Amos"], and Stam [we would know that] he has four Amos in every direction.

Question: [To prevent] Hezek Re'iyah, why do we require [a wall] four Amos in Bava Basra (2b)?

Answer: Sometimes there is a clump of earth near the wall, and also sometimes he lifts his heel and stands on his tiptoes;

Also, it says here that his body is three Amos, i.e. without his head. (It seems that this is not an independent answer by itself, for the head is less than an Amah, and the eyes are not at the very top. Tosfos ha'Rosh says that once more than three were needed, Chachamim obligated four, but Tosfos did not say so.)

Support #1: It connotes like this in Shabbos (92a). It says that one who carries a load above 10 [Tefachim] is liable, for this is how Bnei Kehas carried;

It was taught that the Aron was nine, and the Kapores (its cover) was a Tefach, and we have a tradition that anything carried on poles, a third is above [the poles] and two thirds are below. It turns out that [the entire Aron] was above 10;

They carried it on the shoulder. Deduct from 18 Tefachim (three Amos, which is the height until the shoulder) two third of the Aron and Kapores, i.e. six and two thirds, and 11 and a third Tefachim remain above the ground.

However, if a person with his head is only 18 Tefachim, the (bottom) of the Aron reaches until below 10, for the head and neck occupy more than one and a third Tefachim!

Support #2: For burial caves we require four Amos [length] in Bava Basra (100b), i.e. with the head and the thickness of the walls of the coffin.

Implied question: The Shi'ur of a Mikveh (which is enough for a person to fit into) is an Amah by an Amah by three Amos! (This connotes that one's total height is three Amos.)

Answer: This is not because one's height is not more than three Amos. Rather, when he enters the water, the water rises, and also he bends his head down a little.

Implied question: It says in the Targum of Megilas Esther (which discusses what occupied the 50 Amos from the top of the scaffold from which Haman and his sons were hung) that Parshandasa was hung in three Amos, and likewise for all of them!

Answer: Their heads were cut off.

Explanation: If not (not all open to Reshus ha'Rabim), those [Chatzeros] that have rights to walk through the other (to get to Reshus ha'Rabim) would forbid it.

Implied question: Why didn't Rav Yehudah establish [our Mishnah] like Rav Sheshes did?

Suggestion: He holds that even in two houses, it is an Eruv according to Beis Hillel.

Rejection: Below (49a), Rav Yehudah says that one who splits his Eruv even into Kelim, it is not an Eruv. Beis Hillel are Machshir only when the Kli was full, and there was more (he was forced to use another Kli)!

Answer: [Rav Yehudah] did not establish [our Mishnah] like Rav Sheshes did, because below [Rav Acha] challenges Rav Sheshes that they are like five who dwell in one Chatzer, and [Rav Yehudah] holds that we are stringent about residents [to say that they forbid if they were not Me'arev, so he cannot answer like Rav Sheshes did].

Implied question: Why isn't this difficult also for Rav Sheshes?

Answer #1: Since [the outer Chatzeros] put their Eruv in the middle [Chatzer], and did not put their Eruvin together, rather, in two houses, the outer ones revealed their intent that they do not want to join together;

However, when the middle [Chatzer] put its Eruv in this [Chatzer] and in this, there is not such revelation of intent.

Answer #2: According to Rav Yehudah, since [the middle Chatzer] put its Eruv in this and in this, it is as if it lives in the outer Chatzeros in their houses, and it becomes the Shali'ach of each one;

According to Rav Sheshes, the middle [Chatzer] is not their Shali'ach. Just the contrary, all of them live in it!

Implied question: It says below (66b) if they put their Eruv in the inner [Chatzer], and an inner person forgot to be Me'arev, both Chatzeros are forbidden. [The one who forgot] cannot be Mevatel to the inner Chatzer, for there is the outer, which forbids on them!

Answer: There is different, for he was negligent.

Explanation #1 (Rashi): This is Rashi's text. He explains that the outer ones Mishtamshos (use) the middle. Mishtamshos is like Meshameshes (serves);

However, the middle is forbidden in both of them, for this one draws it to here, and this one draws it to here, and we do not give two residences to it. Since the outer ones were not Me'arev together, they are separate Reshuyos.

Implied question: Why did Shmuel say "also this is R. Shimon's opinion"?

Answer: R. Shimon permitted only in this way (the outers may use the middle, but not vice-versa).

Implied question: Why does it say that Shmuel taught like he taught elsewhere?

Answer: It is because he holds that the Halachah follows the lenient opinion in Eruv;

If he held like Rav, who said that according to R. Shimon also the middle [Chatzer] is permitted in both of them, he would not say that if it was Me'arev with both of them, it is forbidden with both of them.

Question #1: According to this Perush, his text should say Meshamshos, for two Reshuyos use it (the middle)!

Question #2: We said above (48a) that R. Shimon said as follows to Rabanan. What is different about two Chatzeros, that you argue [with me]?

According to Rav, what is the connection of one to the other? Rabanan did not decree at all, for they permit the outer in the middle! Also, what was the answer "there, there are many residents"?

Question #3: We never heard Shmuel say anywhere that the Halachah follows the lenient opinion in Eruv. Rather, R. Yehoshua ben Levi said so above (46a)!

Strengthening of question: Just the contrary, Shmuel holds below (81b) that whenever R. Yehudah taught regarding Eruv, the Halachah follows him. R. Shimon's opponent here is R. Yehudah, like it says above (47a)!

Answer (to the strengthened question): We can say that since R. Yehudah was not mentioned explicitly, the Klal (general rule) does not apply to it. Shmuel rules like below [like R. Yehudah] only when he is mentioned explicitly.

Question #4: The word "even" is improper, like Rashi himself asked (49a), for it would be better if he did not teach "even", for one can err about this, for it connotes that both are permitted!

Question #5: According to this Perush, Rav and Shmuel argue about how to explain the Mishnah's words "it is permitted with them, and they are permitted with it"! (Tosfos ha'Rosh - the Gemara connotes that they argue about Chachamim's opinion. According to Rashi, they argue about R. Shimon's words.)

Explanation #2 (R. Tam): One Reshus Mishtameshes (uses) two Reshuyos - the middle uses the outer. There is not so much need to decree lest the middle take Kelim of an outer [Chatzer] from one to the other;

However, the outer are forbidden with the middle, lest they come to exchange Kelim that were Shoves in this outer [Chatzer] to this outer [Chatzer].

Implied suggestion: Perhaps the reason Rabanan forbid the outers in the middle is because the outers forbid each other, since they were not Me'arev together;

Or, perhaps the outers are forbidden in the middle because residents of the outer are not in the middle, but the middle may use the outers, for its Eruv makes it frequent with both of them!

Rav Yehudah taught like he taught elsewhere. Above, he established that the middle put its Eruv in this and in this.

Rejection: If so, it is difficult what R. Shimon said to Rabanan "why do you argue with me there"?!

Conclusion: Rather, surely the reason is because we decree, and Shmuel said "even this is R. Shimon's opinion." He permits the outers and the middle with each other, but Rabanan hold that all three are forbidden.

Now, Shmuel teaches like he taught elsewhere. He said that if it was Me'arev with both of them, it is forbidden with both of them, like Rabanan, who say that all three are forbidden. [Rabanan] are R. Yehudah, and Shmuel rules like R. Yehudah regarding Eruv.

However, according to Rav, it is not forbidden with both of them. Even Rabanan permit the middle to use with them.

Question #1 (Ri): "It is forbidden with both of them" connotes that however, they are permitted with it, since [R. Shimon] did not teach "it forbids both of them", like in the Seifa.

Suggestion: We can say that it teaches that it is forbidden with both of them, even though there is not so much reason to decree, and all the more so they are forbidden with it, for there is more reason to decree!

And even so, since they are forbidden to use together only due to a decree, [the middle] does not forbid both (by themselves)!

Rejection: Since he did not say "if it was Me'arev with both of them, it does not forbid both of them", which would connote that [one may carry within any one Chatzer, but] all are forbidden with each other, rather, he taught "it is forbidden with both of them", this surely connotes that however, they are permitted with it.

Question #2: Below (91a), Shmuel said that the Halachah follows R. Shimon, who said that roofs, Chatzeros and Karfifos are one Reshus for Kelim that were Shoves in them, whether or not they were Me'arev, because R. Shimon holds like he taught here, that he does not decree!

Explanation #3: Shmuel said that according to Rabanan, all three are forbidden, for two reasons. The outers are forbidden in the middle, due to a decree, lest they take Kelim of this outer one to the other outer one;

There is no reason to decree to forbid the middle in the outers, lest the middle take Kelim of this outer one to the other, for Stam, one uses his own Kelim, and not another's Kelim, like it explains below (74a) regarding two Chatzeros and a ruin between them.

Implied suggestion: We should decree [to forbid the middle in the outers], lest the outers bring their Kelim to the middle!

Rejection: We do not decree this, for it is a decree for a decree.

Conclusion: Rather, the reason the middle is forbidden with the outers, is because this one draws it to here, and this one [draws it] to here. R. Shimon argues with both of these [reasons].

Support: Shmuel teaches like he taught elsewhere. He rules below like R. Yehudah regarding Eruv. Therefore he says that it is forbidden with both of them, like Rabanan, i.e. R. Yehudah. The reason is because this one draws it to here, and this one to here, like I explained;

However, they are permitted with it, for regarding this he holds like R. Shimon, who does not decree, like [Shmuel] ruled below (91a), that the Halachah follows R. Shimon. Whether or not they were Me'arev, he does not decree.