Opinion: The Rashba notes that Rav and Shmuel understood this reason from the fact that the Gemara did not say the case is where one carried from private domain to private domain through a public domain, as is the case of the argument between Rebbi Akiva and the Rabbanan (4a).

Implied Question: The Gemara in Gitin (79a) regarding a woman on a rooftop who had a Get thrown to her etc. says that this is like Rebbi who says that an object that passes through airspace is as if it was placed there. (Why didn't it give the answer given by Rav and Shmuel?)

Opinion (cont.): The Gemara there does not agree with the opinion of Rav and Shmuel stated in our Gemara that Rebbi only says one is liable if the private domain has a roof.

Observation: According to Rav and Shmuel, it must be that the explanation of the Mishnah in Gitin (ibid.) is that she is divorced because it is considered guarded, as the Gemara states there according to the Rabbanan. The Gemara there says, "The Mishnah could even be according to the Rabbanan. The Rabbanan only argue regarding Shabbos, but the reason here is because it is guarded etc."

Observation: One is not even liable for extending on the same side of the public domain according to the Yerushalmi that requires a second person to accept it from his hand. (See Tosfos 3a, DH "ba'Asosah" who discusses this Yerushalmi at length.)

Question: Even if it is not a private domain, it is still not a public domain! Rather, it is like a Karmelis, just like a pole that is three Tefachim tall and four Tefachim wide. Why, then, is he liable?

Answer: The status of a Karmelis does not apply to vessels, as Rashi explains later regarding, "If his box was placed etc."

Question: This is difficult. What is the one who was asking the question thinking? He must have known that our Mishnah is referring to a case lower than ten Tefachim without having to ask the question from Rebbi Yosi b'Rebbi Yehudah, as anything higher than ten Tefachim is a Makom Petur. There is nobody who says one is liable in such a case!

Question (cont.): If so, what is the question from Rebbi Yosi b'Rebbi Yehudah? It is obvious that it is not a private domain if it is less than ten Tefachim!

Proof: This is as the Mishnah states later (99a) that if someone takes something from the dug out walls of a pit or rock that are ten Tefachim high and four Tefachim wide, or he puts something on top of them, he is liable. If they are less than these measurements, he is exempt. It is clear that Rebbi Yosi b'Rebbi Yehudah is discussing a case that is higher than ten Tefachim!

Explanation: Rebbi Avahu understands that when he holds it in his hand it is considered held (by his body and not on the ground).

Proof: If it is not, why should it matter if the poor person took from his hand? Even if the homeowner put into it, the poor person will be liable when he takes it out since his hand is presumably less than three Tefachim off the ground as well, as their hands are probably in the same area.

Proof (cont.): When the poor person takes from the hand of the homeowner that is less than three Tefachim, the hand of the poor person is also lower than three Tefachim. In such a case, even if the homeowner gives into the hand of the poor person he will be liable.

Explanation: One must explain that the case is regarding a ditch that is in the public domain, as many people are using it. This would be according to the opinion (8b) that something that can be used, even though it is difficult to use it, is called usable. Alternatively, it could be that many people go there (and it therefore has the status of a public domain).

Explantion (cont.): However, regarding a ditch that was a Karmelis or a Makom Petur, since his body is there his extended hand that is in the public domain cannot be considered like the public domain, as it is considered to have the status of his body. This is despite the fact that his hand is less than three Tefachim from the ground. This is due to Rebbi Avahu holding that something in one's hand is considered part of his body (not on the ground), as I explained in the previous Tosfos.

Question: Why didn't the Gemara suffice with this without quoting the previous statement?

Answer: I would think that specifically regarding putting something down is one's hand considered like a place that is four by four Tefachim, not regarding taking it from one's hand.

Explanation #1: This means that just as the first of two people involved in an act of carrying is exempt because he did not put the object down, so too if someone grabbed an object from its path and did not let it continue to where it was supposed to land, it is not considered that he put it down. This is because it did not land due to his throwing it.

Explanation #1 (cont.): On the other hand, it could be considered like the act of one person. Since he did both the uprooting and the placing it down, he should be liable, unlike two different people who each did half an act of carrying.

Explanation #2: Rabeinu Chananel has a different text, "like two people and he is liable." This is because the Beraisa stated earlier that if he stood in his place and accepted it, he is liable. Here, too, if he caught it and did not stop it from its path, he should be liable as his plan was done.

Explanation #2 (cont.): Alternatively, he could be considered like one person and he is exempt, as he is like someone who moved something from his right to his left hand. Even though he did this while moving it four cubits, perhaps he is exempt.

Question: According to Rava in our chapter who did not decree in a Karmelis due to not making a decree upon another decree, as is apparent from the Gemara later (11b) regarding a tailor not going out with his needle, why specify a Sefer? Anything should be permitted to if it is gathered in his hand, since even if he does not gather it in his hand it is only prohibited according to Rabbinic law!

Question (cont.): One can only say this is talking about a doorstop in a Karmelis, as Abaye concludes in Eiruvin (98a).

Answer: It says a Sefer to teach us that even a Sefer must be gathered in his hand or it is forbidden. This excludes the opinion of Rebbi Shimon who says there (Eiruvin ibid.) that Rabbinic prohibitions on Shabbos are not enforced when they are to the detriment of holy writings.

Explanation: The Ri explains that the case is where many people use it for their loads, causing it to have the status of a public domain.

Implied Question: This is despite the fact that we say in Bava Metzia (9b) that a boat is resting, and the water is pushing it. (Why isn't the nut like a boat?)

Answer: Regarding acquisition it is looked at differently, as it is not called a "walking courtyard." This is because the fact that a courtyard acquires is derived from "Yad," and a person causes the Yad to move.

Answer (cont.): However, here we derive from the Mishkan, and in the Mishkan what mattered was whether it was a normal way for people to put away their things. The Gemara's question is merely whether it is normal for one who has a nut in a vessel to purposely have this vessel float on water (i.e. to store it there), even though it is certainly not considered put down since we hold that riding (or in this case floating) is like walking.

Proof #1: The Gemara later (153a) also implies that if a person puts an object on another person while he is traveling, it is not considered as if he put it down. This is as the Gemara states there, "he puts it on it when it is moving, and takes from it when it is standing."

Proof #2: We also say later (80a) that if a person carries an amount of ink that can be used to write two letters and he writes those letters while walking he is liable, as his writing is considered like he put it down. This implies that only because he wrote the letters and therefore put them somewhere they will stay forever is this considered putting down. However, if he spilled the ink into a different vessel it would not be considered putting it down, as he is walking.

Observation: Since the Mishnah said the case was when a Tevul Yom touched the oil and it does not say a "Sheini" touched the oil, it implies that oil is considered a liquid. This is because a different type of Sheini would have caused the oil to be a Rishon.

Proof: This is also implied in Pesachim (14b, see there).

Observation (cont.): The difficulty with this that is apparent from the Gemara in Menachos I explained in Pesachim (ibid.).

Question: The Ri has difficulty with this. Why do we need this reason (that walking is like standing)? We should say that it is understandable that Ben Azai will never say one is liable, as the Gemara therefore asks this question on the Rabbanan. If we say this reason because Ben Azai admits regarding throwing, we still do not know that he admits regarding throwing. If we did, the questioner should also ask his question on Ben Azai regarding throwing and extending. Where do we find etc.?

Answer: The Ri answers that the question is as follows. It is understandable according to Ben Azai that even if we find this was done in the Mishkan one will be exempt, as walking is like standing. However, according to the Rabbana we should ask, where do we find etc.?

Opinion #1: The Yerushalmi asks that according to Ben Azai one will never be liable for carrying four cubits in the public domain, as every cubit that he carries is considered as if he put the object down and he will be exempt! The Yerushami answers that Ben Azai will say he is liable if he carries while jumping four cubits (at once) in the public domain.

Opinion #2: Our Gemara does not consider the Yerushalmi's question to be difficult, as stated later (96b) that being liable for carrying four cubits in the public domain is a Halachah l'Moshe mi'Sinai. One therefore cannot ask how one is liable (according to Ben Azai). Similarly, one cannot ask according to Rebbi Akiva, who holds that an object passing through airspace is as if it is placed in that airspace, how it is possible that one who throws an object four cubits in the public domain is liable. We do not say that it is like it is put down within the four cubits in the public domain.

Question: The Riva is unsure regarding the following. Since we do not say regarding walking four cubits in the public domain that walking is like standing, even though Ben Azai holds it normally is like standing, will Ben Azai hold one is liable for carrying four cubits in the public domain if he stands in order to rest?

Question (cont.): Similarly, if he did not stop outside the four cubits, for example if someone else took it out of his hand, do we say that walking is like standing outside of the four cubits or not?

Question (cont.): Similarly, when something in airspace is deemed put down according to Rebbi Akiva, is it considered put down outside the four cubits even if a different person took it or a dog took it or it was burned, since we do not say this within four cubits?

Observation: The Rashba understands that Rebbi Yochanan who says earlier that someone who moves his objects from one corner of his house to another corner and then decides (after uprooting the objects) to take them out of his house is exempt from carrying on Shabbos must not agree with Ben Azai. This is because according to Ben Azai who says walking is like standing he would be liable. This is clearly indicated by the Gemara in Kesuvos (31a).