1) THE DIFFERENCE BETWEEN A "KAR" AND A "KESES"
OPINIONS: The Mishnah (62a) states that when a Jew rents his donkey to a Nochri who places his container of Yayin Nesech on the donkey, the Jew may benefit from the payment he receives from the rental. The Gemara suggests that this is permitted because it is unusual for a person to place his wine on a donkey, and thus the Jew did not expect to receive money for such a service. The Gemara questions this from a Beraisa that states that when one rents out his donkey, the person who rents it is entitled to place his clothing ("Kesuso"), wine, and food for the trip on the donkey. This implies that placing wine on a donkey is included in the normal usage of a donkey! Abaye answers that although it is normal for a person to place wine on a donkey, it is not that usage of the donkey for which a person pays when he rents a donkey. This is evident the fact that one would not receive a lower price if he would bring no wine on the trip.
TOSFOS (DH Hachi Garsinan) quotes RABEINU TAM who questions the wording of the Gemara as it appears in our text. Why does the Beraisa -- when it teaches what items are acceptable to place on a rented donkey -- need to list "Kesuso" ("his clothing")? It should be obvious that a person does not need to remove his clothes when he rents a donkey! Even if the Beraisa refers to bringing along additional clothing, that, too, should be obvious; if he frequently wears the other garment, it is obvious that he may bring it with him on the donkey. If it refers to a garment that he does not frequently wear, then the Gemara should clarify that the Beraisa permits bringing even clothes that he does not normally wear. Rabeinu Tam therefore maintains that the correct Girsa of the Gemara should be "Kisto" and not "Kesuso." What exactly is "Kisto"?
(a) TOSFOS explains that "Kisto" is commonly translated as a large, mattress-like cushion upon which one rests. A "Kar," which is often mentioned together with "Keses" ("Kisto"), is commonly translated as either a small cushion used for sitting, or a small pillow used for resting the head.
(b) Tosfos states that this translation of Keses is erroneous. Rather, the opposite is the correct way of translating the terms. A Keses is either a small cushion or small pillow, and a Kar is a large, mattress-like cushion. Tosfos cites a number of proofs for these definitions. The Mishnah in Kelim (28:5) discusses a case of one who made his Kar into a sheet and his Keses into a cloth. This indicates that the Kar which one is able to convert into a sheet is the larger of the two. In addition, the Gemara in Eruvin (100b) discusses the specific curses which Chavah received for her share in the sin of eating from the Etz ha'Da'as. One of these curses is that she was made into a "Kar" for her husband. This Gemara implies that the woman is more than just a place for the husband to rest his head, but rather she serves as a Kar that is large enough for the entire body. Third, the Gemara in Gitin (47a) states that Rebbi Shimon ben Levi was resting on his stomach, and he commented that his stomach is his Kar. How is that to be understood if a Kar is a small pillow for the head?
Tosfos' explanation is also that of the ARUCH (Erech Kar) and RABEINU YEHOSEF, quoted by the MELECHES SHLOMO (with whom the Meleches Shlomo agrees).
(c) The opinion that Tosfos quotes in the "name of the people" seems to be the opinion of the RAMBAM (in Perush ha'Mishnayos to Shabbos 4:2). The Rambam explicitly states that a Kar is a head pillow and a Keses is larger. However, he does not identify the specific the use of a Keses.
The TOSFOS YOM TOV (Mikva'os 10:2) explains that the Rambam maintains that both a Kar and a Keses are head pillows, and a Kar is merely a smaller one that a Keses.
(The opinion of the BARTENURA is unclear. In Shabbos (ibid.) he explains like the Rambam, while in Mikva'os (10:2) he translates these words like Tosfos.) (Y. MONTROSE)
2) POURING WINE INTO THE VESSELS OF NOCHRIM
QUESTION: The Gemara relates that the father of Rav Acha brei d'Rav Ika used to sell wine to Nochrim, which involved pouring the wine into the containers of the Nochrim. In exchange for his service of pouring the wine and ensuring that they could cross the river for free, the Nochri purchasers would let him retain the barrel from which he poured the wine (when it was customary to give the barrel together with the wine).
How was he allowed to pour the wine into the vessels of the Nochrim and then keep the barrel? This should have constituted working with Yayin Nesech, which is forbidden! Abaye answers that he was permitted to do so because his work involved his own, permitted merchandise.
How does Abaye's answer justify the practice of the father of Rav Acha? What difference does it make if the barrel belonged to Rav Acha? At the moment he poured the wine into the vessel of the Nochri, the wine became Yayin Nesech!
(a) RASHI (DH b'Didei) explains that the wine does not become forbidden until it reaches the bottom of the Nochri's vessel. Until that moment, a Jew may pour the wine in exchange for keeping the barrel.
What is the reason behind Rashi's assertion? Why does the wine become forbidden only when it reaches the bottom of the vessel?
1. The RITVA understands that Rashi maintains that whenever wine lands in a container owned by a Nochri, it immediately becomes forbidden. He explains, according to Rashi, that once the wine is in the air of the vessel, the action of pouring is deemed completed. At the time the wine reaches the bottom of the vessel, the pourer was no longer doing any act of pouring of forbidden wine. This also is the explanation given by the TUR (YD 137) in the name of his father, the ROSH (Avodah Zarah 2:20). (See the TERUMAS HA'DESHEN (1:201), who questions how this explanation is consistent with the words of the Rosh, and see the BEIS YOSEF (YD ibid.) for a possible explanation.)
The Ritva, Tosfos (DH Ki Ka Tarach), and many others question this explanation. Even if the wine becomes forbidden only when it reaches the bottom, there is a principle called "Nitzok Chibur," which means that the column of flowing liquid creates a connection (see 72b). According to Rashi, the wine being poured should become forbidden before it reaches the bottom, at the moment that it is poured, because as it is poured it falls into wine which is already forbidden (at the bottom of the barrel).
Tosfos answers that this is not a difficulty, because the Halachah follows the view of Rebbi Shimon ben Gamliel who maintains that wine which mixes with Yayin Nesech may be sold, and one may benefit from the proceeds except for the value of the amount of Yayin Nesech in the mixture.
Alternatively, Tosfos answers that the Halachah, as Rabeinu Tam rules, follows the view that Nitzok is not a Chibur. (See Ritva for additional answers).
2. The MAHARAM explains that Rashi understands that the Gemara is concerned with a different problem altogether. The Nochri purchasers often had leftover wine in the bottom of their containers. Abaye is not addressing the problem of pouring the actual wine that was just purchased. Rather, he is addressing the problem of pouring the wine into the leftover Yayin Nesech in the containers of the Nochrim. Abaye explains that the pouring itself is not problematic, since the wine becomes forbidden only when it mingles with the Yayin Nesech at the bottom of the container.
(b) The Ritva says that there is no need for Rashi's explanation. The Halachah follows the view of the Chachamim (29b) who maintain that Jewish wine in Nochri vessels is not forbidden from benefit. The Ritva states that Abaye explains simply that since the father of Rav Acha ensured that the Nochri customers could not touch the wine while he was pouring it, he never encountered a problem of Yayin Nesech. (See this opinion as stated more explicitly by the ME'IRI.) The Ritva notes that since this is the correct explanation, the question regarding "Nitzok Chibur" is no longer relevant. (Y. MONTROSE)