Explanation: Now we retract from what we said that they argue about when the walls of the boat were decreased, and one who jumps [to another boat];

Now, also Rabah permits to go [on the entire boat], for Rabah agrees about a moving boat.

Question: Here, Rabah does not hold according to Shmuel that Mechitzos [of a boat] are made to keep out water. Below (90a), Shmuel says that one may carry in a boat only within four Amos, because the Mechitzos are made to keep out water!

Answer #1: There, [they enclose] more than Beis Sa'atayim. The reason that they are made to keep out water is not considered like Mukaf l'Dirah (surrounded for the sake of residence);

Here, [they enclose] less than Beis Sa'atayim. We do not need Mukaf l'Dirah.

Answer #2: [Shmuel] retracted (from what he said there), like we say there.

Explanation #1: R. Zeira was not concerned for this question. He explains that [R. Yehoshua and R. Akiva] wanted to be stringent on themselves like their teaching.

Explanation #2: R. Zeira holds that Techumim do not apply above 10 [Tefachim]. They wanted [to be stringent] lest the boat go in shallow water (below 10), like we say below.

Opinion #1 (Rashbam): One may board a boat during the day on Erev Shabbos, even though the boat will leave the Techum on Shabbos, for the boat goes by itself, and [the passenger] does not do anything;

This is only if he does not go outside the boat. The entire boat is like four Amos.

Implied question: A Beraisa in Shabbos (19a) teaches that one may not embark on a boat less than three days before Shabbos!

Answer: That is like Beis Shamai, who permit Melachah on Erev Shabbos only if it will finish before Shabbos;

However, according to Beis Hillel, who permit [starting Melachah] until sundown, even though the Melachah is done on Shabbos, one may embark.

Implied question: In that Beraisa, Rebbi and R. Shimon ben Gamliel argue! (They were from Beis Hillel.)

Answer: They argue according to Beis Shamai.

Support: Also the Yerushalmi connotes that the Beraisa is like Beis Shamai, for it teaches "one may not embark to Yam ha'Gadol (the Mediterranean) on Thursday or Friday. Beis Shamai forbid even on Wednesday, and Beis Hillel permit;

[Beis Hillel] permit even on Friday. They address the first Tana. If they addressed Beis Shamai, they are just like the first Tana!

Opinion #1 (cont.): The Rashbam permitted to enter the boat even on Shabbos, since he does not do anything. However, he has only four Amos, since he was not Shoves in the Mechitzos from before Shabbos.

Implied question: Beis Hillel permit only before sundown, but not on Shabbos!

Answer: That is because it is like Amirah l'Nochri (telling a Nochri to do Melachah), which is Shevus (forbidden mid'Rabanan).

Rebuttal #1: In Shabbos (139b) it connotes that it is forbidden, regarding the Chacham who went and slept on the ferry and it went to the other side, and oversaw his Peros, and said that he intended to sleep;

It is permitted because it is a scheme about a mid'Rabanan law. A Chacham will not come to overtly transgress.

Inference: It is forbidden l'Chatchilah even within the Techum, since it does not mention going outside the Techum;

It connotes that there is no Isur to oversee Peros. It is permitted even for wages, like we say (151a) "guard my Peros in your Techum, and I will guard your Peros in my Techum." (The scheme was needed only to board the ferry.)

Explanation #1 (Ritzva): The reason one may not enter a boat is because it resembles swimming in the river. It is forbidden due to a decree lest one make a swimmer's flotation barrel.

Explanation #2: [It is forbidden] lest he conduct the boat, and this is like taking it four Amos in Karmelis.

Rebuttal #2 (of the Rashbam's Heter to enter a boat on Shabbos): The Yerushalmi that I brought connotes that one may not enter a boat on Shabbos, since the first Tana did not say "not on Shabbos, and not on Erev Shabbos", which is would connotes that Beis Hillel permit even on Shabbos, just like it mentioned "not on Erev Shabbos" due to Beis Hillel.

Remark (Ri): Those people who light Neros on a boat on Erev Shabbos and eat there and rely on this to go on a boat on Shabbos, they do improperly, for in any case they embark on Shabbos!

Opinion #1: The Rashbam explained that one who enters a boat on Shabbos has only four Amos.

Rebuttal (and Opinion #2): We hold like Rav, who said that even a Dir or Sahar, and he was not Shoves in [its] Mechitzos, the Halachah follows R. Gamliel;

Source #1: Below (44a), we ask simply about Nechemyah ben Chanilai, surely he did not have enough people [to make Mechitzos from the Techum until where he was standing]. If he had enough people, Rav said that the Halachah follows R. Gamliel regarding a Dir or Sahar!

Source #2: Below (47b), regarding the rams that came to Mevarkesa, we considered the entire city like four Amos. This is like Rav.

Implied question: R. Chananel rules like Shmuel, and he brought a proof from Chananyah, who said "last night, my uncle (R. Yehoshua, decided that the Halachah follows R. Gamliel regarding a boatm and R. Akiva regarding a Dir and Sahar)"!

Answer #1: The Halachah does not follow him, for we say in Shabbos (40a) that a Hachra'ah (mediating opinion, which we always follow) in a Beraisa is not a Hachra'ah.

Note: There, R. Yochanan taught that the Halachah follows the Machri'a, and he explicitly ruled like R. Yehudah. He needed to rule explicitly, for one might have thought only in a Mishnah, but not in a Beraisa. Tosfos there explains "one might have thought [that the Klal, that the Halachah follows the Machri'a, is] only in a Mishnah, but not in a Beraisa." Normally, the Klal is even in a Beraisa, but there was a reason to think that the Beraisa there is an exception. Our Tosfos must explain "one might have thought [that the Halachah does not follow R. Yehudah, for the Halachah follows the Machri'a] only in a Mishnah, but not in a Beraisa."

Answer #2: [Chananyah's] uncle, i.e. R. Yehoshua, was one of the parties who argued. He cannot be Machri'a.

Support: The Rif rules [like Rav], for the Halachah follows Rav [against Shmuel] in Isurim.

Suggestion: The Rashbam wanted to permit to enter a wagon on Shabbos, and a Nochri will drive it outside the Techum.

Retraction: He retracted, for perhaps they will encounter bandits, or he will forget and descend [from the wagon], and he has only four Amos.

Pesak (Ri): One may not enter even on Erev Shabbos [in order that he will go outside the Techum on Shabbos]. Only regarding a boat, one may enter on Erev Shabbos. Here (a wagon), since it is possible for him to descend, it is forbidden;

However, regarding a boat, one need not be stringent, even if it he happens to encounter dry land and he could descend (and the reason why we are stringent about a wagon applies), Rabanan did not distinguish regarding a boat.

Remark: Also, if an animal leads the wagon, obviously it is forbidden to use animals, lest he break a branch [to hit the animal to make it go].

Question: Why is the law different regarding a Kohen? We do not forbid him to drink wine forever [lest Mashi'ach come and he will need to serve in the Mikdash], like it says in Sanhedrin (22b) "what can I do? His Kilkul (what ruins the Kohen) is his Tikun." I.e. so many years have passed, and the Mikdash was not rebuilt (so we are not concerned lest it be built today);

Why are we not concerned lest [Mashi'ach] ben David come, like we are here?

Answer: There, there is no Isur. Another Kohen can [serve], or [this Kohen who drank] can sleep a little [and then he may serve];

However, here [if he drinks and Mashi'ach comes], he transgresses his Nezirus.

Support: Also in Beitzah (5b) we say that [we forbid an egg laid on the first day of Rosh Hashanah even on the second day, for] we are concerned lest the Mikdash be rebuilt [and we will not accept testimony of Rosh Hashanah after Minchah, so there will be two days of Kedushah, and he will eat the egg b'Isur).

Answer #2 (R. Tam): "The day that Ben David comes" means that it is proper for him to come. Now, it is not difficult at all.

Support: This resolves what people ask "why is he forbidden? Mashi'ach ben Yosef must come first, and he did not come yet!"

Question: Below, we ask "also a weekday should be permitted, for Eliyahu did not come yesterday." Even so, it was proper [for Ben David] to come [today]!"

Answer: We ask according to the conclusion. We establish that he vowed on Shabbos. Therefore, we ask that [also] on a weekday, we should permit the day he vowed, for he is not proper to come that day, since Eliyahu did not come yesterday.

Question: Perhaps [Eliyahu] came on Erev Shabbos, and he will announce [the coming of Mashi'ach] on Shabbos!

Answer: "Hine Anochi Shole'ach Lachem Es Eliyahu ha'Navi Lifnei Vo Yom Hash-m" connotes that on the day he comes, he will announce.

Citation (Pesachim 13a - Beraisa): [Chachamim say that when Erev Pesach is on Shabbos, we destroy Taluy (Safek Tamei) Chametz before Shabbos. R. Eliezer said] "according to you, we should not burn Taluy Terumah. Perhaps Eliyahu will come and tell us that it is really Tahor!"

Explanation: We can say that also [R. Eliezer] is unsure [whether or not Techumim apply above 10. If they do not, Eliyahu could come on Shabbos].

Note: Chaim l'Yisrael (45b) asks that Eliyahu comes to every Bris Milah! Perhaps then, he has the status of an angel, and is not bound by the law of Techumim, and similarly when he visits every Pesach Seder. Chachamim understood that when he comes to herald Mashi'ach, he will be like a person. ]

Implied question: [Why did the other] Tana answer "Yisrael are assured [through tradition] that Eliyahu will not come on Shabbos, Erev Shabbos or Erev Yom Tov"?

Note: Our text here and there says only that he will not come on Erev Shabbos or Erev Yom Tov, due to toil. Since one may not toil on Shabbos for Yom Tov, he should be able to come on Shabbos (if Techumim do not apply above 10), even if it is Erev Yom Tov! The Tana who says to burn Teluyos before Shabbos, why is he sure that he will not come on Shabbos?)

Answer: It seems to me that he means that just like [Eliyahu] will not come on Erev Shabbos or Erev Yom Tov, due to the toil of preparing the Seudah [of Shabbos or Yom Tov], likewise he will not come on Shabbos before the meal, due to the toil of the meal of Shabbos.

Implied question: This is unlike R. Meir, who says below (45a) that one who stopped on the road and got up [after dark] and found that he is close to (within the Techum of) a city, if he did not intend for this, he may not enter it!

Answer: (It is even like R. Meir.) Here they intended to have Shevisah in the city. They relied on the tube of R. Gamliel.

Explanation #1 - Inference: Here it connotes that Rav Nachman bar Yitzchak is not Stam Rav Nachman, and likewise in several places. This is unlike...

Explanation #2 (Rashi in Gitin 31b): Rav Nachman bar Yitzchak said "I do not need them", i.e. the household of the Reish Galusa. Rashi explained that this is because [Rav Nachman bar Yitzchak] was the son-in-law of the Reish Galusa.

Rebuttal: Rav Nachman Stam was the son-in-law of the Reish Galusa, like is proven in Chulin (124a).

Rather, [Rav Nachman bar Yitzchak] said "I do not need them" because he was rich.

Explanation #1 (cont.): Rav Nachman Stam is Rav Nachman bar Yakov, for Rav Nachman Stam was the colleague of Rav Sheshes, and it is proven in the Yerushalmi that Rav Nachman bar Yakov was the colleague of Rav Sheshes.

Support: In the Gemara, we find Rav Nachman bar Yakov mentioned explicitly (with his father's name) only [when he is mentioned along] with Rav Nachman bar Rav Chisda or Rav Nachman bar Yitzchak.

Assertion: This is the correct text. The text does not say "Rav Nachman bar Yitzchak said to him", for here it is obvious to him (the one who explained Rav Chisda's Safek) that a Mechitzah of people is valid;

Afterwards (44a) Rav Nachman bar Yitzchak challenges Rava from "if the wall [of a Sukah] fell [one may not stand up in its place a person." This shows that] it is not a Mechitzah!

Question: Also when there are not enough men, he should go as far as the Mechitzah reaches, and afterwards make another Hekef (wall of men), until he reaches the Techum!

Answer: Since they already did so once, they will know that they do so for this intent (to permit him to return), and it is forbidden from now and onwards, like we conclude at the end of our Sugya (44b).