Sifrei Devarim 232

¹(Devarim 22:11) "You shall not wear shatnez (a mixture), wool and linen together": I might think, he must not wear shorn wool and flax stalks; it is, therefore, written " shatnez ," something that is fulled, spun, and twisted (or woven) ( shua, tavi, venoz [acronym of " shatnez "]). R. Shimon b. Elazar says: (He who wears shatnez ) is perverse (" naloz ") and estranges (" meiliz ") his Father in heaven [play on " noz " (woven)]. Felt cloaks (of mixed materials) are forbidden as kilayim (intermixtures). Even though they do not come under "weaving," they do come under "spinning." ²"You shall not wear": This tells me only of wearing. Whence do I derive that he may not cover himself with it! From (Vayikra 14:19) "and a garment kilayim shatnez shall not come upon you." I might think that he may not throw a bundle (containing shatnez ) over his shoulder (to carry it); it is, therefore, written "You shall not wear." Wearing was included in the general interdict (against shatnez ). Why was it singled out (for special mention)? To use it as the basis for a comparison, viz.: Just as "wearing" is distinctive in that it is of benefit to the body, so, all that is distinctive (is forbidden by reason of shatnez , to exclude throwing it over one's shoulder). ³I might think he may not wear a garment of wool over one of flax, and one of flax over one of wool; it is, therefore, written (woven) "together," but each by itself is permitted. ⁴R. Chananiah b. Gamliel says: Whence is it derived that one may not hatchel strips of wool with strips of flax to belt his thighs even though there is a band of leather separating them? From "together." This is to say that a sack and a basket (joining wool and linen) are considered a union in respect to kilayim .