QUESTION: The Mishnah states that if one covered a pot with insulating material before Shabbos and it "became uncovered," one may cover it again on Shabbos, and it is not considered a new Hatmanah (which is prohibited on Shabbos).
Why does the Mishnah say that the pot "became uncovered," implying that it became uncovered by itself or by accident? Even if one intentionally removed the cover, he should be permitted to replace it on Shabbos. We find that if one removes a pot from a stovetop on Shabbos, he may replace it afterwards (Mishnah 36b, according to Beis Hillel). The Mishnah here should emphasize that one may re-cover the pot even if he intentionally removes the cover on Shabbos!
(a) TOSFOS explains that the Mishnah is referring to a pot that became uncovered on Friday before Shabbos (and not on Shabbos or during Bein ha'Shemashos). If it accidentally became uncovered on Friday (and remained uncovered until after Shabbos arrived), then one may re-cover it on Shabbos. If, however, one intentionally uncovered it on Friday, he may not return the cover on Shabbos, because it is considered a new Hatmanah and is prohibited on Shabbos. (However, if the pot was covered until after Bein ha'Shemashos, one may intentionally uncover it and re-cover it on Shabbos as necessary.)
(b) The SEFER HA'TERUMAH and the SEMAG cited by the HAGAHOS MAIMONIYOS (Hilchos Shabbos 3:6 and 4:2) explain that the Mishnah is referring to a pot that became uncovered on Shabbos. The Mishnah is teaching that if it became uncovered by accident -- or even intentionally -- on Shabbos, one may replace the cover. The reason the Mishnah mentions that it was un-covered "unintentionally" is in order to teach that if it became uncovered on Friday even unintentionally (and remained uncovered until after Shabbos arrived), one may not cover it on Shabbos. They cite support for this explanation from the Yerushalmi.
HALACHAH: The SHULCHAN ARUCH (OC 257:4) rules stringently, like the second opinion. Therefore, if the pot became uncovered even by itself on Friday before Shabbos, one may not cover it on Shabbos.


OPINIONS: The Beraisa at the end of the chapter says that one may not crush ice on Shabbos, but one may put it inside a cup to melt. What is the problem with crushing it, and why is one permitted to place it in a cup to melt?
(a) RASHI writes that one is prohibited to crush ice because it appears as though one is creating a new entity ("Nolad"), water, on Shabbos. The prohibition is limited to a positive action that produces a new entity. One may, however, let water become created itself by placing the ice in a cup. Since it is not a genuine case of Nolad (but just "looks like" Nolad), the water produced is not Muktzah. As long as no active crushing is involved, one is permitted to allow the ice to melt.
(b) The RASHBA cites the SEFER HA'TERUMAH who says that making water from ice is a genuine case of Nolad, and the water produced in such a manner is Muktzah. The RITVA explains that according to this approach, when the Beraisa says that one may let ice melt in a cup, it is referring to a cup that already has water in it. Since the newly created water (from the melting ice) mixes immediately with the water already in the cup and is never an independent entity, one is permitted to let the ice melt in such a manner.
(c) The RASHBA himself says that the problem is that crushing ice gives the appearance of "Sechitah," squeezing an object to obtain its juice. If crushing ice was permitted, people might err and think that it is also permissible to squeeze fruit to obtain juice (which is an Isur d'Oraisa). However, one is permitted to crush ice inside of a cup if it is filled with water (because the resulting liquid becomes mixed immediately and is not seen, and it is not obvious that he has created liquid). Likewise, letting the ice melt by itself even when it is not in a cup is permitted (it does not resemble Sechitah because no action of squeezing has been done). That is, the Rashba accepts the lenient rulings of both Rashi and the Sefer ha'Terumah: ice may be left to melt by itself, or crushed manually into a cup with water.
HALACHAH: The SHULCHAN ARUCH (OC 320:9) cites the explanation of Rashi (a). The MISHNAH BERURAH (320:34) cites the Rashba (c) and says that one may leave ice to melt in the sun, or crush ice into a cup of water. The Mishnah Berurah (320:35) then cites the REMA (OC 318:16) who quotes the Sefer ha'Terumah that crushing ice may be forbidden because of Nolad, and therefore one should only let it melt in a cup that already has water in it.
QUESTION: The Gemara discusses whether an animal may walk in Reshus ha'Rabim with "Shemirah Yeseirah" (items that assist in restraining or protecting it, which provide more than enough restraint or protection) on Shabbos. Is such attire considered a "Tachshit" (common accessory), which an animal may wear in Reshus ha'Rabim on Shabbos, or is it considered a "Masuy" (load), which an animal may not take into Reshus ha'Rabim on Shabbos.
The Gemara quotes Rebbi Yosi who said that four animals may go out with a halter ("Afsar"), and it attempts to prove from his statement that "Shemirah Yeseirah" is considered a Masuy. Rebbi Yosi's statement that four animals may go out with a halter implies that they may not go out with another type of restraint, such as one that provides excessive restraint. The Gemara refutes this proof and suggests that Rebbi Yosi meant that only these four animals may go out with a halter, but other types of animals may not go out with a halter (because it does not provide protection for them at all).
The Gemara then cites another short Beraisa that says that a "Luvdekim and camel may go out with a halter." Why is this Beraisa mentioned here? What is it adding to the current discussion?
(a) This Beraisa indeed is not relevant here, but since the Gemara has cited Rebbi Yosi's list of animals that may go out with a halter, the Gemara records another list.
(b) The MAHARSHA and MAHARAM explain that this Beraisa is proving that "Shemirah Yeseirah" is prohibited, since it implies that a camel may not go out with an iron nose-ring, but only with a halter. It is true that Rebbi Yosi's list provides no clear proof, since it might be implying that other animals may not go out with a halter, for Rebbi Yosi explicitly emphasized that "these animals may go out with a halter," excluding all other animals. The short Beraisa, however, does not specify that only "these" animals may wear a halter, and thus it is not excluding other animals from wearing a halter. Rather, it is teaching that a camel may go out with a halter, but not with an iron nose-ring.
(c) The SEFAS EMES and KORBAN NESANEL (#2) explain that this Beraisa is proving that Rebbi Yosi's list of "four animals that go out with a halter" is incomplete. Even a Luvdekim may go out with a halter. Accordingly, when the first Tana said that four animals may go out with a halter, the implication could not have been that only these animals may go out with a halter but not any other animals. Rather, the implication must be that these four animals may not go out with an iron nose-ring ("Shemirah Yeseirah"), as the Gemara originally assumed.
QUESTION: The Gemara relates that Levi, the son of Rav Huna bar Chiya, and Rabah bar Rav Huna were traveling on donkeys from one town to another. Levi's donkey galloped ahead of Rabah's donkey. Rabah became upset that Levi went ahead of him and neglected to give him the respect due to him. Levi indirectly informed Rabah that it was not done on purpose, but that his donkey was difficult to control.
Why was Levi required to let Rabah go ahead of him in the first place? Even though Rabah was deserving of respect, the Gemara in Berachos (47a) clearly states there is no obligation to let the more respected person go first on the road! Why, then, was Rabah upset?
ANSWER: TOSFOS cites RABEINU TAM who answers that the Gemara in Berachos, which says that there is no obligation to let the more respected person go first while traveling, applies only when each person is traveling by himself and they happen to meet up with each other. However, if they are traveling together as a group, then certainly one must give deference to one who is greater and allow him to travel at the head.