1) HEATING AN EMPTY POT
QUESTION: The Gemara cites a Beraisa which says that every participant is liable in a case in which, on Shabbos, one person brings the fire, another person brings the wood, another places the pot on the fire, another brings the water to put in the pot, another places the spices into the pot, and another person mixes it all. The Gemara asks why the person who places the pot on the fire is liable, if the pot is empty and he cooks nothing. The Gemara answers that the Beraisa means that he brought a new pot and placed it on the fire, thereby making it stronger and completing the utensil.
RASHI (DH u'Mishum) explains that the Gemara means that the person who places the empty pot on the fire transgresses an Isur d'Rabanan -- the Gezeirah not to heat a shingle. Rashi apparently understands that the act of placing a pot on a fire constitutes an Isur d'Rabanan. The Beraisa, however, states that one is Chayav for the act. This clearly implies that the act of placing the empty pot on the fire constitutes an Isur d'Oraisa. Although the word "Chayav" in the Beraisa can be interpreted to mean that one is Chayav for Malkus mid'Rabanan (as the Gemara says in Shabbos 40b), this is not the simple meaning of "Chayav." For what reason does Rashi interpret the Beraisa in a manner different from its simple meaning? (ROSH YOSEF, BIGDEI YOM TOV)
ANSWER: The Gemara earlier records a dispute concerning the reason for why the Mishnah prohibits heating shingles on Yom Tov in order to roast meat on them. The Gemara explains that the Mishnah refers to new shingles. One opinion says that heating new shingles is prohibited because the heating process reinforces them, and it is considered as though one thereby completes the formation of the item (Tikun Kli). Another opinion says that it is prohibited because the heating process tends to cause the shingles to crack (and become unusable), and one will have performed a "Tircha she'Lo l'Tzorech," an unnecessary act of exertion on Yom Tov.
Both opinions agree that the shingles which the Mishnah prohibits one from heating are new. If the act of heating a new clay object completes it and constitutes an Isur d'Oraisa (Libun Re'afim), then why does the other opinion find it necessary to explain that the prohibition of heating shingles is not because of Libun Re'afim, but because of an Isur d'Rabanan that the shingles might crack? Certainly the two opinions do not argue over why one heats shingles, for such a question could be easily resolved by asking a potter. Moreover, it is obvious that an earthenware shingle (or pot) is useless before it is fired, and that firing it renders it a usable utensil (see 32a).
To answer this question, Rashi explains that the "new" shingles to which the Gemara refers are not shingles which have not yet been fired. Rather, they are shingles which have been fired but are still new. The prohibition of heating these shingles is only an Isur d'Rabanan. They are certainly fit to be used without further heating, and therefore they are considered to be finished already and one does not "complete" them when he heats them. Rather, the only problem with re-firing new shingles is "Tikun Kli d'Rabanan" (like the cases in the Mishnah on 32b), as re-firing the shingles strengthens them more to some degree. The other opinion, that re-firing the shingles is prohibited because the shingles might break, maintains that there is no problem of "Tikun Kli d'Rabanan" because no physical change in the shingle is evident after it is re-fired. Since the Gemara compares heating a new pot to heating shingles, Rashi finds it necessary to explain that heating the new pot is also prohibited only d'Rabanan.
(The RAMBAM (Hilchos Yom Tov 3:11) and RIF were apparently bothered by Rashi's question of how the Amora'im could argue about whether or not there is an Isur against heating new, unfired shingles on Yom Tov. To resolve this question, they explained that according to the opinion that the Mishnah's Isur against heating shingles is because it reinforces them, the Mishnah is not discussing new shingles at all (for it would be unnecessary for the Mishnah to teach that firing not-yet-fired shingles is prohibited mid'Oraisa). Rather, the Mishnah is discussing old shingles (MAGID MISHNEH, based on an inference from the fact that the Rambam and Rif do not mention that the Mishnah is discussing new shingles). When the Gemara says that one may not heat a new pot because of Libun Re'afim, it refers to the Isur of "Tzarich l'Badkan," i.e., that the pot may crack from the heat and one will have performed a "Tircha she'Lo l'Tzorech" (LECHEM MISHNEH ibid.). According to the Rambam and Rif, the Beraisa prescribes Malkus d'Rabanan for the one who heats the pot, and not Malkus d'Oraisa, as Rashi explains.)
2) TEARING A CLOTH INADVERTENTLY ON YOM TOV
QUESTION: The Gemara cites a Beraisa which states that one may shatter a nut inside of a cloth on Yom Tov, and there is no concern that the cloth will tear. RASHI (DH v'Ein Chosheshin) explains that there is no concern that the cloth will tear because even if it does tear one has not performed an Isur d'Oraisa. (In order to be an Isur d'Oraisa, one must perform an act of "Kore'a Al Menas Litfor." Here, he does not tear it in order to sew it up again differently, and therefore he is permitted l'Chatchilah to shatter the nut inside the cloth.
Why does Rashi explain that the reason why one may shatter the nut inside the cloth is because even if the cloth tears he has not performed an act of "Kore'a Al Menas Litfor"? Rashi should give a much more basic reason for why there is no concern that the cloth will tear: the act is a "Davar she'Eino Miskaven" (he has no intent to tear the cloth, and it is not a Pesik Reshei, an unavoidable outcome, that the cloth will tear), and therefore the act is permitted l'Chatchilah, as Rashi himself writes earlier (33a, DH v'Hilchasa), in accordance with the opinion of Rebbi Shimon. The exemption of "Davar she'Eino Miskaven" applies to all Melachos and not just to Kore'a, while the reason of "Kore'a Al Menas Litfor" applies only to the Melachah of Kore'a. Why does Rashi mention the unique exemption in the laws of Kore'a, and not the general exemption of "Davar she'Eino Miskaven"? (REBBI AKIVA EIGER in GILYON HA'SHAS)
ANSWER: The CHILUFEI GIRSA'OS (in the back of the Vilna edition of the Gemara) answers that Rashi's explanation here is consistent with his opinion elsewhere. In Yoma (34b, DH b'Chol ha'Torah), Rashi writes that even according to Rebbi Yehudah who prohibits a "Davar she'Eino Miskaven," the act is prohibited only in the case of an Isur d'Oraisa. Rebbi Yehudah permits one to do an Isur d'Rabanan in a manner that is "Eino Miskaven" (see Tosfos there who argues).
Rashi here says that one may shatter the nut even according to Rebbi Yehudah because there is no Isur d'Oraisa involved. That is, Rashi indeed permits one to shatter the nut because, as Rebbi Akiva Eiger says, the act is a "Davar she'Eino Miskaven." Rashi mentions that the act is not "Kore'a Al Menas Litfor" merely to show that even Rebbi Yehudah permits this case of "Davar she'Eino Miskaven" because it is an Isur d'Rabanan. (See also the SHA'AR HA'TZIYUN to OC 508:8.)
Why, though, does Rashi find it necessary to explain the Beraisa according to the opinion of Rebbi Yehudah?
The Chilufei Girsa'os suggests that Rashi is bothered by the fact that the Beraisa specifically permits one to tear a cloth in a manner that is "Eino Miskaven," which is an Isur d'Rabanan since it is not done "Al Menas Litfor." However, if the Beraisa's intention is to teach that one is permitted to do a "Davar she'Eino Miskaven," then it should have discussed a case in which the act is an Isur d'Oraisa! It must be that the Beraisa follows the opinion of Rebbi Yehudah who maintains that a "Davar she'Eino Miskaven" is prohibited, and in this case it is permitted only because the act involved is an Isur d'Rabanan. Rashi is saying that the act is permitted because, as Rebbi Akiva Eiger asks, it is a "Davar she'Eino Miskaven." Rashi adds that it is not "Kore'a Al Menas Litfor" merely to show that even Rebbi Yehudah permits this case of "Davar she'Eino Miskaven" because it is an Isur d'Rabanan.
RAV YEHUDAH LANDY suggests an even simpler reason for why Rashi wants the Beraisa to conform with the opinion of Rebbi Yehudah, even though the Halachah does not follow his opinion. This Beraisa is actually a Tosefta. It is the conclusion of the Tosefta cited a line earlier which prohibits fixing a broken skewer. Rashi (DH v'Ein Metaknin) is bothered by the fact that the Halachah is that one is permitted to fix a broken skewer, in accordance with the view of Rebbi Yehudah who permits Machshirei Ochel Nefesh (on 28b). Why, then, does the Beraisa prohibit fixing a skewer on Yom Tov? Rashi offers two solutions: First, the Tosefta is expressing the opinion of the Chachamim who disagree with Rebbi Yehudah and prohibit Machshirei Ochel Nefesh on Yom Tov. Alternatively, it is expressing the Halachic opinion, that of Rebbi Yehudah who permits Machshirei Ochel Nefesh on Yom Tov, but it is discussing a skewer that was broken before Yom Tov. Machshirei Ochel Nefesh that could have been done before Yom Tov are not permitted on Yom Tov.
Rashi wants the beginning of the Tosefta to comply with the opinion of Rebbi Yehudah with regard to Machshirei Ochel Nefesh, since his opinion is the Halachic opinion in this regard. However, Rashi cannot explain that the beginning of the Tosefta follows Rebbi Yehudah's opinion if the end of the Tosefta does not. Therefore, when he comments on the end of the Tosefta (which discusses shattering a nut inside a cloth), Rashi explains it according to the opinion of Rebbi Yehudah with regard to "Davar she'Eino Miskaven," even though his opinion is not the Halachic opinion in that regard.