1) ONE WHO THROWS FROM ONE RESHUS HA'RABIM TO ANOTHER VIA RESHUS HA'YACHID
QUESTIONS: The Beraisa says that if one throws an object from one Reshus ha'Rabim to another Reshus ha'Rabim and the object passes through a Reshus ha'Yachid, he is Chayav if the object travels at least four Amos in Reshus ha'Rabim. If it travels less than four Amos in Reshus ha'Rabim, he is Patur.
RASHI explains that when the object travels less than four Amos in Reshus ha'Rabim in this case, he is not Chayav for Hotza'ah (for transferring an object from Reshus ha'Rabim to the Reshus ha'Yachid through which it passed), because the Tana of the Beraisa does not agree to the concept of "Kelutah k'Mi she'Hunchah."
Why does Rashi explain that the Tana of the Beraisa maintains that an object that passes through the airspace of a certain domain is not considered as though it has rested there? In this case, the thrower did not want the object to land in Reshus ha'Yachid. Since his intention was not fulfilled, he should be exempt even if we rule that "Kelutah k'Mi she'Hunchah"!
Furthermore, why does Rashi write that we see from the end of the Beraisa that this Tana does not agree to the concept of "Kelutah k'Mi she'Hunchah"? We see this from the beginning of the Beraisa! If the Tana would agree to the concept of "Kelutah," the thrower would be exempt, because the object that he threw is considered to have landed in Reshus ha'Yachid before it traveled four Amos in Reshus ha'Rabim!
ANSWERS:
(a) The RITVA asks these questions on Rashi's explanation. As a result of these questions, the Ritva explains that the inference that the Tana does not agree to the concept of "Kelutah" is from the beginning of the Beraisa. The beginning of the Beraisa says that the thrower is Chayav. However, if the object is considered as though it rested in the Reshus ha'Yachid through which it passed, then he should not be Chayav. In the case of the end of the Beraisa, though, he would be exempt even if the Tana does not maintain "Kelutah k'Mi she'Hunchah," because the thrower did not have any intention for the object to land in Reshus ha'Yachid. Only from the beginning of the Beraisa do we see that the Tana does not maintain "Kelutah." (That is, if the Tana maintains "Kelutah k'Mi she'Hunchah," then the thrower would be Chayav even though the thrower did not want the object to land in Reshus ha'Yachid, because, in practice, it did rest there. In the end of the Beraisa, though, "Kelutah" would not make a person Chayav, because he had no intention for the object to land in Reshus ha'Yachid.)
(b) Rashi clearly disagrees with the Ritva (see DH v'Iy l'Hacha). Rashi maintains that if the thrower did not want the object to land in a particular Reshus, then it would not be considered "Kalut" (contained) there. "Kelutah" does not apply when the person does not want it to rest in that domain (see Rashi to 97b, DH ul'Mai). How, then, can the Gemara infer that the Tana of the Beraisa does not maintain "Kelutah k'Mi she'Hunchah," if "Kelutah" does not apply when the person did not want the object to land in that domain? It must be that the Beraisa is discussing a case of "Kol Makom she'Tirtzeh, Tanu'ach," where he wanted it to rest wherever it happened to land, and, therefore, the object that is "Kalut" in the airspace of that domain is considered to have landed there. That is why we can infer that the Tana does not agree to "Kelutah" from the fact that the Tana rules that the person is Patur for Hotza'ah.
Our second question, however, remains unanswered. We should be able to infer from the beginning of the Beraisa that the Tana does not agree to "Kelutah." If the thrower wanted it to land wherever it landed, then "Kelutah k'Mi she'Hunchah" should make him exempt. From the fact that he is Chayav for carrying four Amos in Reshus ha'Rabim, it is evident that the Tana does not hold of "Kelutah". Why, then, does Rashi still infer this only from the end of the Beraisa?
It must be that Rashi maintains that "Kelutah" applies only as a Chumra, and not as a Kula (as the TOSFOS YESHANIM writes on 4b). "Kelutah" cannot work to exempt a person from liability for Hotza'ah (a "Kula," leniency). Rather, it can only work to make a person Chayav. Thus, in the first case of the Beraisa, "Kelutah" cannot make the thrower exempt, even if the Tana normally maintains "Kelutah k'Mi she'Hunchah." Consequently, it is only from the case of the end of the Beraisa (where "Kelutah" would serve to make him Chayav for Hotza'ah) that we can infer that the Tana does not maintain "Kelutah." (M. KORNFELD)
2) A ROOF OVER PART OF RESHUS HA'RABIM
QUESTION: Rav says that "Reshus ha'Rabim Mekurah," a Reshus ha'Rabim that has a roof over it, is not considered Reshus ha'Rabim. The Gemara attempts to disprove this from the wagons that were used for transporting the pillars of the Mishkan. The areas underneath, between, and to the sides of the wagons were considered Reshus ha'Rabim even though those areas were roofed (the pillars on the wagons extended over the sides of the wagons). The Gemara concludes that we cannot prove from the wagons that Reshus ha'Rabim Mekurah is considered Reshus ha'Rabim, because the wagons still had some areas that were not covered (such as the gaps between the pillars that extended over the sides of the wagons), and perhaps it is only those areas that are called Reshus ha'Rabim.
However, this does not answer the question of the Gemara. While there were areas that were not covered that constituted areas of Reshus ha'Rabim, the wagons also had areas that were covered, and they are still called Reshus ha'Rabim!
ANSWER: TOSFOS (DH Hanicha) answers in the name of the RI that we do not derive the concept of Reshus ha'Rabim from the wagons. Rather, we derive the concept of Reshus ha'Rabim from the encampment of the Leviyim, as the Gemara describes earlier (96b). The wagons merely reveal to us the measurements of Reshus ha'Rabim (16 Amos wide; 99a). As long as some part of the area around the wagons was uncovered, that area is considered Reshus ha'Rabim; the areas that were covered, though, do not need to have the status of Reshus ha'Rabim.
3) "ATABA'I"
OPINIONS: The Gemara says that it is possible for more than three Tefachim to separate between the pillars that were placed on the wagons, if they were arranged "b'Ataba'i." What does "Ataba'i" mean?
(a) RASHI quotes his teachers who explain that "Ataba'i" refers to the rings that were on the pillars (on the inner side of the pillars, one on the upper section and one on the lower section). The Gemara refers to when the pillars were stacked in two pairs of stacks (one pair in the front of the wagon and one in the back), and each pair was comprised of two stacks of pillars laid back to back so that the rings of each pillar faced the other direction. Even though the rings of the two inner stacks of pillars (the one at the front of the wagon and the one at the back) both faced inwards towards each other, there was enough room between the pillars (one Amah) so that they did not rub against each other.
(b) Rashi himself explains that "Ataba'i" refers to wooden clips used to hold paper, which were fashioned by cutting lengthwise through the middle of a splinter of wood (much like old fashioned wooden clothespins). The meaning of the Gemara, though, is the same as Rashi's teachers explain.
(c) TOSFOS explains that "Ataba'i" refers to support rails on the wagon. The wagons were outfitted with guard rails that were attached to the sides (or to each end of the wagon, as the Gemara concludes) to keep the pillars from slipping off. The Gemara means that before the pillars were loaded on to the wagons, when only the guard rails were affixed, the area below the wagon is considered Reshus ha'Rabim.

98b----------------------------------------98b

4) THE "YERI'OS HA'IZIM" THAT COVERED THE MISHKAN
OPINIONS: The Gemara discusses two opinions of how the Yeri'os ha'Izim (goat-hair coverings), which were 44 Amos long, were draped over the Mishkan. Everyone agrees that two Amos hung over the eastern side (like a "Kalah Tzenu'ah," a modest bride). The question is what the back of the Mishkan looked like. How did the Yeri'os hang there?
(a) According to Rebbi Nechemyah, in the back of the Mishkan (the western side) one Amah dragged along the ground. (Rebbi Nechemyah maintains that the pillars were one Amah thick on top as they were on bottom, and thus an extra Amah of the Yeri'os was used up to cover the one-Amah thickness of the pillars of the western side. Accordingly, the length of the Yeri'os covered the following: 30 Amos (the length of the Mishkan), 10 Amos (the height of the pillars), 2 (the length the Yeri'os hung on the eastern side), 1 (the thickness of the pillars of the western side, plus 1 (the Amah that the Yeri'os dragged on the ground on the western side).)
(b) Rebbi Yehudah, in contrast, maintains that the pillars were pointed at their tops (and were only one Etzba thick). According to Rebbi Yehudah, two Amos of the Yeri'os dragged on the ground.
(c) Rashi in Parshas Terumah cites a third opinion. According to the "Beraisa Meleches ha'Mishkan," the pillars on the eastern side of the Mishkan stood outside of the Mishkan, and the Yeri'os hung over them as well. They therefore added one Amah to the area which the Yeri'os covered, and thus, according to Rebbi Nechemyah's opinion that the pillars were one Amah wide at their tops, the Yeri'os did not drag on the ground on the western side at all. (The Gemara here argues and maintains that the pillars on the eastern side of the Mishkan stood inside the 30-Amah length of the Mishkan, and therefore they did not add an Amah to the length of the Mishkan's roof.)

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