1) "KIL'AYIM" IN THE VESTMENTS OF THE KOHEN
QUESTION: The Gemara discusses whether a Kohen is permitted to derive benefit from the Bigdei Kehunah while he is not performing an Avodah. Does deriving benefit from the Bigdei Kehunah constitute Me'ilah or not? The Gemara suggests various proofs to permit a Kohen to derive benefit from the Bigdei Kehunah. The first proof is from the Mishnah (68b) which states that the Kohen Gadol may wear the Bigdei Kehunah when he reads from the Torah (which is not an Avodah) on Yom Kippur. The second proof is from a Beraisa which says that the Kohanim are permitted to sleep in the Bigdei Kehunah and to walk around while wearing the Bigdei Kehunah. Finally, the Gemara cites a Beraisa which says that the Kohanim are permitted to place the Bigdei Kehunah beneath their heads when they sleep.
The Gemara rejects its final proof and says that the Beraisa does not mean that the Kohanim are permitted to place the Bigdei Kehunah underneath their heads, but rather beside their heads. The Gemara supports this interpretation of the Beraisa by pointing out that the Beraisa cannot mean that the Kohanim may place the Bigdei Kehunah literally underneath their heads, because if they place the Bigdei Kehunah there they will transgress the prohibition against deriving benefit from Kil'ayim (the Avnet was made of wool and linen).
Why does the Gemara address the problem of Kil'ayim only at this point? If wearing the Bigdei Kehunah (when not performing an Avodah) poses a problem of Kil'ayim, why does the Gemara earlier suggest that the Kohen may wear the Bigdei Kehunah even when he is not performing an Avodah? Even if he transgresses no prohibition of Me'ilah, he still transgresses the prohibition of Kil'ayim! Why does the Gemara address the problem of Kil'ayim only now, when it discusses placing the Bigdei Kehunah underneath one's head?
(a) TOSFOS in Menachos (40b-41a, DH Techeles) and the TOSFOS YESHANIM here write that the Gemara here provides strong support for the opinion of RABEINU TAM. Rabeinu Tam asserts that since one is permitted to wear a garment which contains Kil'ayim in order to fulfill the Mitzvah of Tzitzis, he may wear that garment even at a time when he fulfills no Mitzvah (such as the nighttime). (Rabeinu Tam maintains that the reason why one may wear a garment with Kil'ayim in order to fulfill the Mitzvah of Tzitzis is not merely because of the principle, "Aseh Docheh Lo Ta'aseh," but because the Torah completely permits the prohibition of Kil'ayim on a garment with Tzitzis.) Similarly, with regard to Kil'ayim in the Bigdei Kehunah, since the Kohen is permitted to wear the Bigdei Kehunah with Kil'ayim when he performs the Avodah he may also wear the Bigdei Kehunah with Kil'ayim when he does not perform the Avodah. The prohibition against benefiting from Kil'ayim applies only when the Kohen does not wear the Bigdei Kehunah but merely warms himself with them in some other way. The Torah permits Kil'ayim only when the Kohen wears the Bigdei Kehunah, but not when he sits on top of them or rests his head on them.
(See also RA'AVAD, Hilchos Kil'ayim 10:32 and Hilchos Klei ha'Mikdash 8:10, who rules like Rabeinu Tam and argues with the Rambam on this point.)
(b) The MEFARESH in Tamid (27a) says that the Gemara's question here with regard to Kil'ayim refers back to the beginning of the Sugya. The Gemara indeed could have asked this question earlier, but it knew that the answer to the question would apply to the entire Sugya (to all of the cases of Kohanim who wear the Bigdei Kehunah with Kil'ayim). The Gemara answers that the garment with Kil'ayim is made of a very hard material, to which the prohibition of Kil'ayim does not apply.
The Mefaresh understands that not only is one permitted to lie on Kil'ayim when the garment is made of a hard material, but the prohibition does not apply even when one wears a garment made of a hard material. Since such a garment does not warm the person while he wears it, it does not constitute forbidden benefit from Kil'ayim. (See following Insights.)
2) THE PROHIBITION OF LYING ON "KIL'AYIM"
QUESTION: The Gemara cites a Beraisa which states that although the Torah forbids one only from wearing Kil'ayim upon his body, the Rabanan prohibited even lying or sitting on Kil'ayim out of concern that perhaps a thread of Kil'ayim will become wrapped upon the person in such a way that he will benefit from wearing it. The Gemara asks that perhaps the Isur d'Rabanan applies only when the Kil'ayim is directly underneath the person, but if another object separates between him and the Kil'ayim he may lie or sit on it. The Gemara responds with a statement of the Tana'im that even when ten sheets are spread over the Kil'ayim, one sheet on top of the other, one may not lie on the uppermost sheet.
Why does the Beraisa say that the reason for the Isur d'Rabanan against lying on Kil'ayim is because of the concern that a thread of Kil'ayim will wrap up onto the person's body? If one is forbidden to lie even on top of sheets which cover the Kil'ayim, the prohibition obviously is not due to the concern that a thread might wrap up onto one's body, because many sheets separate his body from the Kil'ayim! Rather, the Isur is merely a Gezeirah to prevent one from taking the Kil'ayim from underneath him and wearing it. Why, then, does the Beraisa say that the reason is because a thread of Kil'ayim might become wrapped around part of his body?
(a) The RITVA in Beitzah (14b) says that the Gezeirah which prohibits lying on top of ten sheets which are on top of Kil'ayim is actually a "Gezeirah l'Gezeirah," a rabbinical decree made to safeguard another decree. The original Gezeirah of the Rabanan prohibited lying directly on a garment of Kil'ayim lest a thread of Kil'ayim wrap up onto his skin. The Gezeirah which prohibits lying on the uppermost of ten sheets which are on top of Kil'ayim was enacted in order to prevent one from lying or sitting directly on Kil'ayim, which in turn is prohibited lest a thread wrap onto his skin. (The two Gezeiros are considered to be one Gezeirah -- "Kula Chada Gezeirah" -- since they were enacted at one time.)
(b) The RAMBAM (Hilchos Kil'ayim 10:12) appears to understand that even if a garment of Kil'ayim is underneath ten sheets, there still is a concern that a thread from the Kil'ayim might reach the top of the sheets and wrap around one's skin. Accordingly, only one Gezeirah was enacted. This also appears to be the opinion of TOSFOS (DH Kashin).
The Rambam and Tosfos are consistent with their own opinion as expressed elsewhere. They maintain that one is prohibited from lying directly on top of a garment of Kil'ayim even if it is very hard. One is permitted to sit on top of it only when another object separates between his skin and the hard garment of Kil'ayim. They consider sitting on Kil'ayim a form of "Ha'ala'ah," placing the garment on one's body, because there is no logical reason to differentiate between a garment on top of one's body and one's body on top of a garment. As long as one's flesh touches the garment, it is considered "Ha'ala'ah." According to this opinion, no Gezeirah is necessary to prohibit one from sitting on Kil'ayim because of the reason that a thread might wrap up onto one's body, since the prohibition of Kil'ayim itself prohibits one from sitting on Kil'ayim. Why, then, was such a Gezeirah enacted? It must be that the Gezeirah that a thread might wrap up onto one's body was enacted in order to prohibit one from lying on a garment of Kil'ayim when it is underneath several sheets.
(c) The RAN in Beitzah (14b) infers from the words of RASHI there (DH Shema Tikarev) that the prohibition against lying on Kil'ayim lest a thread wrap up onto one's body is d'Oraisa and not merely d'Rabanan. When the Beraisa teaches that "the Chachamim said that it is forbidden [to lie on Kil'ayim]," it means that it is forbidden because it is a doubt in a case of an Isur d'Oraisa. In the case of Kil'ayim underneath ten sheets, there is no Isur d'Oraisa but only a Gezeirah that one not come to sit on the garment of Kil'ayim itself.
(d) The RAN himself, however, suggests that the Gezeirah against lying on top of sheets which are on top of a garment of Kil'ayim is a Gezeirah to prevent "Ha'ala'ah" -- to ensure that one does not pick up the garment and wear it. It is unrelated to the concern that a thread will wrap onto one's body. There is no concern for a thread in this case because the Kil'ayim is separated from his body by other sheets.
The concern that one might pick up and wear the Kil'ayim, however, applies only to a type of garment that is normally worn, but not to sheets. If the Kil'ayim underneath the sheets is itself a sheet, one is prohibited only to sit directly on top of it. There is no concern that one might pick it up and wear it, but rather there is a concern that since he is sitting directly on the Kil'ayim a thread might wrap up onto him. In contrast, one may not sit on an item of clothing of Kil'ayim even when it is underneath ten sheets, because in such a case the Gezeirah that he might wear it applies.
This explanation is supported by the text of the Beraisa which says, "Even ten sheets, one on top of the other, and Kil'ayim beneath them [is prohibited]." This implies that the prohibited item itself is not a sheet but a different type of garment (a wearable one) made of Kil'ayim.
3) "KIL'AYIM" MADE FROM A HARD MATERIAL
OPINIONS: The Gemara explains that a Kohen does not transgress the prohibition of Kil'ayim when he lies on the Avnet, because the Avnet is made from a hard material.
When is one permitted to benefit from Kil'ayim made from a hard material?
(a) The RA'AVAD (on the Rif, Beitzah 15a) explains that, mid'Oraisa, there is no prohibition of Kil'ayim made from a hard material. Mid'Oraisa, one is permitted even to wear such Kil'ayim. The Rabanan, however, prohibited one from wearing it, but they did not prohibit one from lying or sitting on it. Mid'Oraisa, one is prohibited from wearing a soft material of Kil'ayim, and the Rabanan prohibited one from lying or sitting on it. If the material is a bit soft and a bit hard, one is prohibited to wear such a garment mid'Oraisa, but one is permitted to sit on it even mid'Rabanan. The Rabanan did not prohibit sitting on such material because it is uncommon ("Lo Shachi'ach").
(b) RASHI (DH Shari) here writes that one is permitted to place Kil'ayim of a hard material on one's body ("Ha'ala'ah") even though one normally is prohibited mid'Oraisa from placing Kil'ayim on one's body. "Ha'ala'ah" is forbidden only when it is done in a manner similar to the way a garment is worn, for only in such a way does it give a person some form of pleasure (it provides warmth).
Rashi implies that wearing Kil'ayim ("Levishah") is always forbidden, even when the material is hard, because (as the TOSFOS RID in Beitzah writes) when one wears an item he derives benefit not only from the warmth that it provides but from the protection that it affords or from the honor that it brings him. In the case of "Ha'ala'ah," however, the only benefit one derives from the cloth is the warmth.
(c) TOSFOS in Beitzah (15a) and the TOSFOS YESHANIM here explain in the name of RABEINU TAM that whenever an Isur d'Rabanan of Kil'ayim applies (such as in the case of lying down on a normal garment of Kil'ayim), the Rabanan permitted one to use the Kil'ayim if it is made of a hard material. In contrast, any form of Kil'ayim which is Asur mid'Oraisa remains Asur mid'Oraisa even when it is a hard material. Therefore, the Rabanan permitted one to sit on Kil'ayim (an act which normally is prohibited mid'Rabanan) or to wear a garment made from threads of wool and linen which were pressed but not woven (which is prohibited mid'Rabanan), if it is a hard material.
(d) The RA'AVAD in Tamid (27b) permits one only to lie on or sit on Kil'ayim of a hard material. He maintains that only "Hatza'ah" is permitted when the material is hard. Any other form of the prohibition of Kil'ayim d'Rabanan remains prohibited even when the material is hard (such as wearing a garment of pressed threads which were not woven). He says in the name of Rabeinu Efraim that the threads of a hard cloth do not have a tendency to wrap up around the person's body, and therefore the Gezeirah against lying on Kil'ayim does not apply to hard material.
(e) The RAMBAM (Hilchos Kil'ayim 10:13) rules that wearing Kil'ayim of a hard material is forbidden mid'Oraisa. One is permitted only to lie on or sit on hard Kil'ayim ("Hatza'ah") but not to wear it ("Levishah") or place it on top of his body ("Ha'ala'ah"), as the Ra'avad in Tamid rules.
Moreover, the allowance to lie on or sit on hard Kil'ayim applies only when the material does not touch the person's skin. According to the Rambam, one may not sit directly on top of the Kil'ayim (with no intervening material). (The Ra'avad in Tamid suggests that the reason why the Rambam prohibits sitting directly on hard Kil'ayim is because he maintains that "Ha'ala'ah" applies whenever the Kil'ayim is in direct contact with the person's skin, whether the garment is on the person or the person is on the garment. "Ha'ala'ah" is forbidden mid'Oraisa, and therefore it remains forbidden even when the Kil'ayim is a hard material.)