Midrash su Levitico 19:19

And Moses said unto the children of Israel: “See, the Lord hath called by name Bezalel the son of Uri” (Exod. 35:30). May it please our masters to teach us: How far must a person go to eliminate mixed materials (shatnez)?¹A biblical injunction prohibiting the wearing of a garment made of wool and linen. The law also proscribes the planting of heterogeneous plants in the same field. R. Simeon the son of Yohai concluded from the verse Neither shall there come upon thee a garment of two kinds of stuff mingled together (Lev. 19:19) that a man is prohibited from donning an outer garment of mixed material even though he puts it on over a hundred other garments. However, if he should put it on beneath his other garments, without the mixed material touching his body, he is permitted to do so, for it is said: Neither shall there come upon thee a garment of two kinds of stuff mingled together. The words upon thee signify that it may not be worn as an outer garment but that it may be placed underneath (i.e. closer to the body). The Holy One, blessed be He, said to Israel: Keep My commandments and My statues. Why? Because the consequence of a good deed is another good deed, but the result of committing a sin is another sin. Ben Azzai stated that one good deed results in another good deed, and one sin produces another sin. R. Meir said: For every good deed a man performs, an angel is assigned to watch over him. If he does one good deed, one angel is assigned to him, and if he performs many good deeds, many angels are assigned to him, as it is said: For he will give His angels charge over thee (Ps. 91:11). Every time a man increases the number of good deeds he performs, he adds to his good name. You find that a man is known by three names: the name by which his father and mother call him, the name by which other men call him, and the one he earns for himself; the most important name is the one he earns for himself.²His good deeds are apparent to all.

R. Joshua of Sikhnin said in the name of R. Levi, “There are four things that the evil drive would refute [as irrational], and for each of them is written [the word,] huqqah (i.e., an unquestioned statute).⁸⁴Although Huqqah is normally translated simply as “statute,” the word more fully denotes a command that demands implicit and unquestioned obedience. Huqqah is therefore translated “unquestioned statute” throughout this section. Now these concern the following: (1) the nakedness of a brother's wife, (2) diverse kinds, (3) the scapegoat, and (4) the red heifer.”⁸⁵PR 14:12; Numb. R. 19:5; see Yoma 67b. In regard to the nakedness of a brother's wife, it is written (in Lev. 18:16), “You shall not uncover the nakedness of your brother's wife”; [yet if the brother] dies without children [it is written] (in Deut. 25:5), “her brother-in-law shall have sexual intercourse with her [and take her for a wife].” And it is written about the sexual prohibitions (in Lev. 18:5), “And you shall keep [all] My unquestioned statutes [...].” In regard to diverse kinds, it is written (in Deut. 22:11), “You shall not wear interwoven stuff, [wool and flax together]”; yet a linen cloak⁸⁶Gk.: sindon. with [wool] tassels is permitted.⁸⁷See Numb. 15:37-38. And for [this commandment also] it is written, [that it is] an unquestioned statute. [Thus it is written (in Lev. 19:19),] “You shall keep My unquestioned statute. You shall not mate your cattle with a different kind…, [nor shall you wear a garment with diverse kinds of interwoven stuff].” In regard to the scapegoat, it is written (in Lev. 16:26), “And the one who sets the azazel-goat free shall wash his clothes”; yet it is [the goat] itself that atones for others. And for [this commandment also] it is written (in Lev. 16:34), “And this shall be to you an unquestioned statute forever.” In regard to the red heifer, where is it shown? Since we are taught (in Parah 4:4), “All engaged with the [rite of the red] heifer from beginning to end render [their] garments unclean”; yet it is [the heifer] itself that purifies [what is] unclean. And for [this commandment also] it is written, [that it is] an unquestioned statute. Thus it is written (in Numb. 19:2), “This is an unquestioned statute of the Torah.”

R. Samuel the son of Nahmani said that R. Jonathan stated: Whoever rebukes his companion for religious reasons earns a share of divine grace, as it is said: He that rebuketh a man shall in the end find more favor (Prov. 28:23). And furthermore a thread of divine favors will be drawn about him, as is said: He shall find favor. Scripture says: Mine ordinance shall ye do (Lev. 18:4). These are ordinances which, if they were not enumerated in the Torah, ought to have been. Scripture is speaking here of idolatry and blasphemy. My statutes shall ye keep, to walk therein (ibid.). These are the commandments against which the evil inclination contends, and against which the peoples of the earth rebel. These are: the wearing of garments made of wool and linen,¹²The law of shatnez; see Lev. 19:19. This commandment and all the following ones are disregarded as irrational by non-Jews. the eating of pig,¹³See Lev. 11:7. the spittle of a childless sister-in-law,¹⁴After one has refused to marry his brother’s widow under the law of levirate marriage; see Deut. 25:5–10. mixing seeds,¹⁵Deut. 22:9–11. stoning an ox for killing a human being,¹⁶Exod. 21:29. the heifer whose neck was broken,¹⁷Lev. 14:1–21. the bird sacrifice brought by a leper,¹⁷ a firstling of an ass,¹⁸Exod. 13:13. meat prepared in milk,¹⁹Exod. 23:9. and the goat that has been sent away (the scapegoat).²⁰Lev. 16:1–34. Azazel, the area where the scapegoat would perish. You might maintain that these are unimportant prohibitions. Hence Scripture says: I am the Lord: I have decreed them, and you art not permitted to repudiate them.