(Mishnah): There is only a prohibition of Kilayim (in clothes) when they are a mixture of wool and linen. Only wool and linen can contract the Tumah of Negaim (Tzora'as).

For service in the Beis HaMikdash, Kohanim only wear wool and linen.

Camel hair and wool (of sheep) that became mixed - if the majority is camel hair, it is permitted (with linen); if the majority is sheep's wool, it is prohibited. If it is half and half, it is prohibited.

The same rule applies to Kanbus and linen that are mixed (to be permitted with wool).

Shirayin and Kalach are not Kilayim but they are still prohibited because of Maaris HaAyin (as Shirayin looks like linen and Kalach looks like wool).

Pillows and cushions do not have a prohibition of Kilayim, as long as the skin doesn't touch them directly.

Wearing something only temporarily does not avoid the prohibition of Kilayim.

One may not wear Kilayim even on top of 10 other pieces of clothing, even to avoid paying customs duty.

(Gemara): 'There is only a prohibition of Kilayim etc.' - the pasuk states (Devarim 22:11), "Do not wear Shaatnez, wool and linen together''. I would say that the prohibition is only to wear, but the pasuk says (Vayikra 19:19), "...should not come upon you''. If so, I would say that one cannot place over his shoulder a box that contains a Shaatnez garment, but the pasuk states "Do not wear'' - just as a garment is something that gives benefit to the body, so too only something that gives benefit to the body.

Question: What is the application of the phrase 'should not come upon you'? (The phrase 'Don't not wear' already taught that one may not give benefit to the body.)

Answer (R. Nichah bar Saba/ R. Yochanan citing R. Zeira): If there is a large garment with Kilayim on one end, resting on the ground, and the other end does not contain Kilayim, one may not cover himself even with that side.

I would have said that the prohibition even includes 'sea linen' and canvus (which are 'types of linen')... The pasuk says 'wool and linen' - just as wool doesn't have an accompanying name (meaning that it refers to wool from the sheep family only), so too anything without an accompanying name.

Question: How do we know that sheeps' wool doesn't have an accompanying name (meaning that when the Torah used the word 'Tzemer - wool'' - it was referring only to wool from the sheep family)?

Answer (R. Yehoshua ben Levi): The pasuk states (Melachim 2:3:4), "And Misha, king of Moav, was a Noked''. What is a Noked? Someone with a large amount of sheep. "And he returned to give the king of Israel 100,000 lambs and 100,000 rams with their wool'' - only ram's wool is called wool.

(The Mishnah taught that) only wool and linen can contract the Tumah of Negaim (Tzora'as). As the pasuk states (Vayikra 13:47), "And the garment of wool or the garment of linen''. I would have thought that they become Tameh, whether dyed or undyed, but the pasuk says, "and the garment of wool or the garment of linen'' - just as linen is not (usually) dyed, so too the wool must be undyed.

I would have excluded materials dyed by man but not those dyed naturally; but the pasuk says (Vayikra 13:48), "of linen or of wool'' - just as linen is (off) white (i.e in its nature form), so the wool is white (as it is in its natural form).

We have learned two rules in our Mishnah that sound similar but in fact, they are not...The Mishnah taught that the prohibition of Kilayim applies only to wool and linen, which implies whether or not they have been dyed. But the Tumah of Negaim appliesonly to white garments made of wool or linen.

Question (R. Yona Butzraya to R. Mana): There (Shaatnez) you said it applies whether the garments are colored or white; here (Negaim) it applies only if they are white...

(R. Mana to R. Yona): The pasuk repeated the word 'wool' (concerning Negaim, later in pasuk 59) to instruct that it's compared to linen in that it must be in its natural form, i.e. undyed.

(R. Zeira): (The Mishnah taught that for service in the Beis HaMikdash, Kohanim only wear wool and linen.) The pasuk states (Vayikra 16:4), "He shall wear a holy Bud shirt'' - made from a species that grows as individual stalks. (A Bud is a stalk.)

Question: Perhaps it's referring to wool that also grows individually?

Answer: The pasuk explains in reference to Yom Kippur (Yechezkel 44:17), "and no wool shall be upon them at the gates of the Inner Court and within'' ( - so Bud cannot mean wool as he may not wear them into the Kodesh) - but outside, it is permitted.

What's the source that Kohanim serve wearing Kilayim? The pasuk states (Shemos 39:28-29), "and the hat of linen, and the splendorous high hats of linen, and the linen pants of twisted fine linen, and the belt of twisted fine linen, and blue, purple, and crimson wool''. And it is written (Yechezkel 44:18), "Linen hats shall be upon their heads, and linen pants shall be upon their loins, not in a sweaty place.''

We learn about the linen of the belt, from the linen of the high hats; and we learn those from the linen hats that are mentioned in Yechezkel - just as the color of the crimson wool comes from a living thing (a worm), so too the color of Techeles comes from something living. Just as wool doesn't have an accompanying name; so too linen.