What Is Shatnez?

The biblical prohibition against mixing wool and linen.

In the middle of his rabbinical school admissions interview, a rabbi I know railed against those who “pick and choose” their Jewish practice. “Oh yeah,” replied a member of the admissions committee, “That’s a nice suit — have you checked it for shatnez?”

Implicit in the interviewer’s comment was the recognition that even Jews who keep kosher and observe Shabbat often pay little attention to the prohibition against mixing wool and linen in the same garment. The strangeness of this law, combined with the difficulty of observing it fully, has led many Jews to subject this mitzvah to ridicule.

A Mysterious Word

Even the word “shatnez” is mysterious. The word doesn’t look like a Hebrew one, and linguists have speculated that the term may come from the Coptic words “saht” (woven) and “nudj” (false) or from the Arabic words “shash” (black gauze) and “atmuz” (strong). Yet none of these explanations is universally accepted, and the origin of the word remains unknown.

The rabbis of the Talmud understood shatnez to be a condensed version of three Hebrew words–“shua” (combed or carded), “tavui” (spun), and “nuz” (woven), but this rabbinic answer serves more as a mnemonic device than as an explanation for the origin of the word (Mishnah, Kilayim 9:8). Other rabbinic suggestions for the origins of the word include classifying someone who disregards the laws of shatnez as “naluz (perverse) and turning God against oneself” (Sifra Kedoshim 2:4) or referring to wool “shemaateh” (that covers) the sheep and “nutz” (sprout) of flax (Psikta Zutarta Kedoshim 54a). All of these puns only highlight the difficulty of the word.

The Laws of Shatnez

Two biblical verses prohibit wearing shatnez. In both cases, the references to shatnez appear within the context of other prohibitions against kilayim–mixing two species together:

“You shall not let your cattle mate with a different kind; you shall not sow your field with two kinds of seed; you shall not put on cloth from a mixture of shatnez (Leviticus 19:19).”

“You shall not sow your vineyard with a second kind of seed. . . You shall not plow with an ox and an ass together. You shall not wear shatnez–wool and linen together (Deuteronomy 22:9-11).”

According to the talmudic rabbis, the Torah defined shatnez only as mixing linen made from the flax plant with wool from sheep or lambs.

The rabbis worried, however, that some less-common fabrics, such as silk, might be confused for flax, and therefore prohibited mixtures involving such materials out of fear of marit ayin–giving the appearance of breaking a law. When silk became more common, such concerns disappeared, and later legal authorities eliminated these prohibitions (Shulkhan Arukh Yoreh Deah 298:1).

The laws of shatnez refer only to sewing wool and linen together in the same garment; they do not restrict wearing, for instance, a wool sweater with linen pants. The rabbis did extended the prohibition against shatnez to sitting on cushions made of shatnez or using towels or dishcloths made of shatnez, lest the material rub off onto one’s clothing.

The laws of shatnez are considered so important that one who sees another person wearing shatnez is supposed to strip the offending garment from the wearer, even in public and even if the wearer is one’s rabbi. Some legal authorities, however, softened this stipulation, saying that if the person wearing shatnez is doing so unintentionally then one should wait to speak to this person privately (Shulhan Arukh 303:1 and comment of Moshe Isserles).

Explanations for Shatnez

To the rabbis of the Talmud and later generations, shatnez was the paradigm of a hok–a law without any logical explanation. Defining shatnez as a hok, however, has not stopped generations of commentators from attempting to deduce some spiritual meaning from this strange law. The mystics, for example, saw mixing wool and linen as a symbol of mixing divinity with impurity, or as diluting the heavenly powers (Tikkunei Zohar 109a; Zohar III:86b; Toledot Yitzchak to Leviticus 19:19). Maimonides, the consummate rationalist, speculated that the prohibition against shatnez is a reaction to the custom of pagan priests to wear wool and linen together.

One midrash traces the prohibition against shatnez to the story of Cain and Abel. In the Torah, Abel brings God an offering of sheep, and Cain brings some sort of plant offering. For reasons not explained in the biblical text, God accepts Abel’s offering, but rejects Cain’s. Angry about this show of preference, Cain murders his brother. The midrash specifies that Cain brought God flax seeds, and Abel brought wooly sheep. After Cain killed Abel, God decreed that “the offering of the sinner should not be mixed with the offering of the innocent (Midrash Tanhuma Breishit 9:9).”

Some have viewed the mixing of wool and linen as an unnatural tinkering with the divinely ordained world. Nahmanides warned about anyone who wears shatnez “it is as though this person thinks that God did not perfect God’s world, and that this person wants to help God in the creation of the world by adding creations (Ramban, comment to Leviticus 19:19).” The thirteenth century Sefer haHinukh explained that, at the time of creation, God assigned a heavenly power to guide each earthly creation to fulfill its own mission and growth pattern. The mixing of certain species interferes with these divine plans and weakens the heavenly powers that govern the earthly creations (Mitzvah62).

Rabbi Abraham Isaac Kook believed that the commandment of shatnez offered a glimpse of a future world, in which animals will achieve a higher status:

The legal iniquity in the ownership of property is registered in the prohibition of wearing a mixed garment of wool and linen. We are inhibited from the free mixing of wool, which was taken by robbery from the innocent sheep, with flax, which was acquired by equitable, pleasant and cultured labor. The animal will yet rise in cultural status through the control of a higher moral sense, so that its readiness for idealistic participation with man will not be strange or far away (Fragments of Light).

Priestly Shatnez

While the mixing of linen and wool is generally forbidden, the Torah describes the garments of kohanim (priests) as including both wool and linen. Furthermore, the ancient rabbis taught that tzitzit may consist of wool and linen woven together, and that woolen tzitzit may be attached to a linen garment.  (Menahot 43a) Archaeologists have found tzitzit consistent with this description in sites from the first and second century. The permission to wear shatnez in tzitzit emphasizes that, like the priestly garments, tzitzitare worn in the service of God.

The contemporary Bible scholar Dr. Jacob Milgrom explains as such:

The tzitzit are then an exception to the Torah’s general injunction against wearing garments of mixed seed. . .The resemblance to the high priest’s turban and other priestly clothing can be no accident. It is a conscious attempt to encourage all Israel to aspire to a degree of holiness comparable to that of the priests (“Tzitzit” in Etz Hayim Humash).

Insofar as wool and linen mixtures, like other forbidden products, belong to the realm of God, these are forbidden for ordinary human use. Such materials are specifically prescribed for moments when human beings are able to transcend the world of the ordinary and enter into the divine world.

Discussions of wearing shatnez in tzitzit apply specifically to tzitzit made with t’khelet, a blue dye that may or may not have been rediscovered in the past decade.  Given that most Jews today do not wear t’khelet in their tzitzit, most Jews also no longer wear shatnez in their tzitzit. 

Modern-Day Observances

Modern technology has produced new means of checking clothing for shatnezusing powerful microscopes. The National Committee of Shatnez Testers and Researchers sponsors more than 60 “shatnez labs” in the United States alone, and some shatnez checkers even make house calls. When a lab finds shatnez in a piece of clothing, tailors there are sometimes able to remove the forbidden material and to replace it with a permitted substance. In other cases, the lab may simply tell the owner that the garment is forbidden to wear, but may be sold to a non-Jew.

For the most part, liberal Jews have paid little attention to the laws of shatnez. In the Torah commentary most often used by Reform synagogues, Rabbi Gunther Plaut comments about prohibitions against interfering with creation by mixing species that “such notions are very strange to us who live in the post-Darwinian age (Comment to Leviticus 19:19).”The “Commentary on the Principles of Reform Judaism,” passed by the Central Conference of American Rabbis in 2004, however, reinterprets shatnez as a call for ethical production processes:

To study the mitzvah of shatnez. . . can lead us to examine labels for firms practicing oshek [oppression] through sweatshop labor or payments of a sub-minimum wage.

In a speech to the Conservative Movement’s Rabbinical Assembly in 2001, Rabbi Brad Artson argued that Conservative Jews should reclaim the mitzvah of shatnez as a ritual means of expressing the Jewish principle of distinction between the holy and the profane:

If we want to retain a religion in which ritual is harnessed to the energy of moral depth…we’re going to have to go back to those apparently meaningless rituals and demonstrate their moral base. Separating linen and wool is about making distinctions…It’s about separating a holiness that is inherited simply by being from a holiness that is a holiness of striving and of effort.

While shatnez may never become the most popular or well understood Jewish practice, some modern Jews are attempting to reclaim this practice as a means of expressing ethical commitments, realizing the human potential for holiness, or reminding themselves constantly of their connection with God.

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