Rashi's opinion: We are not concerned lest he sleep in them and pass gas.

Observation: Tamid 27a explains differently, that we are not concerned lest he roll over and fall on them, and there is disgrace to Tefilin.

Implied question: Tana'im argue about this in Bava Kama 12a! (We can say that our Tana holds that they were of linen!)

Answer: He wants to resolve the Mishnah in Tamid (25b), which says that they fold them and put them under their heads, according to all opinions.

Question: If so, why does it say in Erchin (3a) "all are obligated in Tzitzis - Kohanim, Leviyim and Yisraelim"?

The Gemara asked that this is obvious, and answered that the Chidush is Kohanim. One might have thought that since Kil'ayim is permitted to them in Avodah [and the Torah taught Tzitzis next to the Isur of Kil'ayim], they are not obligated in Tzitzis. The Mishnah teaches that this is not so...

Since now we say that [Bigdei Kehunah] are hard, Kil'ayim is not permitted to them!

Answer (R. Tam): Wearing and Ha'alah (putting Kil'ayim on oneself) are forbidden mid'Oraisa even if they are hard;

Hatza'ah (putting Kil'ayim under oneself) is forbidden mid'Rabanan. They did not decree about hard garments.

This is unlike Rashi, who explained that they are hard, and wearing and Ha'alah are permitted.

Implied question (against R. Tam): In Beitzah (14b), a Mishnah says that one may send Kil'ayim on Yom Tov. The Gemara asks what it is useful for, and answers that we discuss hard Kil'ayim.

Answer: Also there, it means that Hatza'ah is permitted.

Question: How can Hatza'ah be permitted? Since it is Kil'ayim mid'Oraisa regarding wearing and Ha'alah, it should be forbidden even to sell them to Nochrim!

(Beraisa): If Kil'ayim was lost in a garment, one may not sell it to Nochrim, or make it a saddle for a donkey, and all the more so one may not spread it under himself.

Answer: That discusses only when it was lost. We are concerned lest his garment tear, and he will sew it onto his garment.

Support: This is like it says in Avodah Zarah (32a), that one may not use a Nochri's wine pouch to make a saddle for a donkey, lest his pouch tear, and he will sew [from the saddle] onto his pouch.

However, if the Kil'ayim was recognized, it would be permitted, like the Mishnah in Kil'ayim (9:4) says that we are not concerned for Kil'ayim in shrouds or saddles.

Question #1: Here we say that even if there were 10 sheets one on top of another, and Kil'ayim under them, one may not sit on them.

Question #2: A Mishnah in Kil'ayim (9:2) says that Kil'ayim does not apply to pillows and blankets.

Answer: Sheets can wrap [onto the body]. We are concerned lest a strand [of Kil'ayim] wrap onto him;

For a donkey saddle, pillows and blankets, it is not common for a strand to wrap [onto him]. Therefore, Chachamim did not decree;

However, if his skin touches [the Kil'ayim], it is forbidden, like it was taught explicitly regarding pillows and blankets "as long as his skin does not touch them." The same applies to a saddle.

Wearing and Ha'alah are forbidden in every case, even if his skin does not touch them. A Mishnah forbids putting a saddle of Kil'ayim on one's shoulder even in order to take out manure [on the Kil'ayim].

Pesak: The Ri answered Rabbeinu Shimon of Yanvila about linen garments with Kil'ayim and wool tufts inside;

Even though the garments on them are linen, one can permit it, like in Beitzah 15a.

Observation: Also Kidushin 54a connotes like this. It is forbidden l'Chatchilah even in the Azarah to wear them not for needs of the Avodah;

It says that Me'ilah does not apply to Bigdei Kehunah, for the Torah was not given to angels. I.e. people cannot be careful to take them off immediately after the Avodah.

Inference: L'Chatchilah, one may not wear them [other than for the Avodah]. People can be careful about this!

Question: We say in Kidushin (66a) that Yanai ha'Melech put on the Tzitz [at a banquet]. This shows that one may wear Bigdei Kehunah even outside the Mikdash!

Suggestion: He [already] became a heretic. (It was forbidden to do so.)

Rejection: The Sugya connotes that he did not become a heretic until later, when he said 'what will happen to written Torah?' [if I kill the Chachamim], and he was not concerned for oral Torah.

Answer #1: According to the opinion (above 7b) that the Tzitz is Meratzeh only when it is on the Kohen Gadol's head, he may wear it at any time [in order to make Korbanos acceptable].

Answer #2 (R. Tam): All agree that he may wear it at any time, for it says "v'Hayah Al Mitzcho Tamid."

Implied question: We need this verse for a different Drashah above (7b), that he may not divert his mind from it!

Answer: Perhaps we learn from the repetition "v'Hayah Al Metzach Aharon", "v'Hayah Al Mitzcho."

Answer #3: I prefer to say that Yanai did improperly to wear the Tzitz;

However, this did not prove that he became a heretic to deny the entire oral Torah, until later, when he said 'what will happen to written Torah?'

Reference: I explained this above (25a) regarding a Chacham sitting in the west [of Lishkas ha'Gazis].

Implied question: Why didn't we answer that this (we may skip...) refers to Torah?

[I.e.] because it says "we do not skip in Torah" [which implies that we may not skip at all], it later explains how much we may skip in Torah, i.e. so the translator will not need to pause.

The Reisha forbids skipping so much that the translator will need to pause.

Answer: Indeed, we could have answered this. Rather, Abaye answered the truth, that we distinguish between one matter and two, like the Beraisa says.