You can’t get too far into a blog about Jewish sewing before you hit the issue of shatnez – the term for a mixture of wool and linen – and the Biblical prohibition against wearing garments that contain shatnez. In fact, we ran into the subject in our very first blog post, which explained how to make a tallit. That post generated a lot of questions, so we thought we’d give you more detail. As it happens, the week we sit down to explain shatnez turns out to be the week when the Torah portion read on Shabbat includes a major exception to the rule. Let’s talk about the rule first. Then we’ll talk about the exception.

The prohibition against wearing shatnez (pronounced shot’nez) appears twice in the Bible:

1. Do not wear a forbidden mixture, where wool and linen are together [in a single garment]. (Deuteronomy 22:11)

2. …Do not wear a garment that contains a forbidden mixture of fabrics. (Leviticus 19:19)

These translations of the verses come from Aryeh Kaplan’s The Living Torah : The Five Books of Moses and the Haftarot.

Kaplan explains that the mixture is “forbidden whether the wool and linen are spun together, woven together, or sewn together.”¹

Although the prohibition is not one of the Bible’s most widely-known commandments, many clothing stores know that some customers observe the prohibition, and they’ll have a garment checked for shatnez if you ask. It’s a particular issue with wool suits, since the threads or the interfacing in the collar can contain linen. I once went suit shopping with a friend at a large mainstream clothing store, and the salesperson brought up the subject of shatnez and offered to have my friend’s chosen suit examined. If you want to determine whether a piece of clothing or fabric contains shatnez, you can find a testing lab through the Shatnez Testers of America.

When we’re sewing clothing, the prohibition comes into play when we’re choosing fabrics and notions. That includes materials for a tallit, or prayer shawl, and, according to this commandment, any garment. It doesn’t apply to things we don’t wear, like challah covers, wedding chuppahs, or stuffed teddy bears. But to observe this commandment when buying materials for an item of clothing, we avoid fabrics that contain both wool and linen. And if we choose a woolen fabric for a garment, we avoid threads, linings, stiffening material, or additional fabrics that contain linen. If we choose a linen fabric, we make sure that any additional fabrics and notions don’t contain wool.

Why?

Although the meaning of this Biblical commandment is fairly straightforward, the reason for it is not. Unlike the commandment to not steal, for example, which helps maintain an orderly society, and the commandment to not eat leavened bread during Passover, which leads us to remember the Israelites’ exodus from ancient Egypt, there is no clear reason for the prohibition against wearing shatnez. It’s classified as a chok, a law that has no rationale. Yet there it is in the Bible, along with Thou Shalt Not Steal and Thou Shalt Not Kill, so Jewish law assumes God means it.

Despite there being no definitive reason for the law, different schools of Jewish thought offer various justifications. Some of the earliest rabbinic leaders² glimpsed an explanation in the Biblical narrative of Cain and Abel. In that Bible story, as you’ll recall, Cain, one of the sons of Adam and Eve, offered a sacrifice of flax to God. And Abel, his brother, sacrificed one of his best sheep. God recognized Abel’s sacrifice but not Cain’s. The Bible doesn’t say why. Naomi Rosenblatt, in Wrestling With Angels, suggests that God might have been testing Cain, assessing whether he made his sacrifice out of a sense of true thanksgiving or to gain God’s approval. We don’t know the reason, but we know the situation didn’t end well. Cain became jealous and killed Abel. According to the early rabbis’ exegesis,³ Cain’s murder of Abel led God to decree that the offering of a sinner –-linen, which is made from flax– should not be mixed with the offering of an innocent ––wool, which comes from sheep.

Kabbalah draws a mystical lesson from this narrative: Combining wool with linen would bring together the forces of good and evil, compromising the essence of each force and causing damage in the spiritual worlds.

Maimonides, the Medieval-era scholar known for clear-eyed rationality, pins the justification on another related commandment, one that forbids Jews from engaging in the practices of the nations that surrounded the Israelites (Leviticus 20:23). Maimonides writes that the priests of those non-Jewish nations wore vestments of wool and linen, so that mixture of materials is forbidden to us.⁴

Exceptions

Yet another explanation relates the law to the garments the Israelite priests wore while serving in the Temple. And here we encounter the major exception to the rule of shatnez that is a subject of this week’s Torah portion, Tetzaveh (Exodus 27:20–30:10). In Tetzaveh, God describes to Moses the garments the priests should wear and how they should be made. The garments include a hat, trousers, tunic, and belt, as well as additional items for the High Priest. And surprise, in a major deviation from the commandment we’ve been examining, the priests’ clothing incorporates wool and linen.

Major commentators⁵ disagree over whether the manner in which the components of some of the garments are combined actually constitutes shatnez, but most agree that the belt worn by the High Priest, which was made of linen and embroidered with wool yarn, is shatnez.

The use of wool and linen in the priests’ Temple garments sets them apart from most Jewish garments and provides the ultimate reason, many commentators suggest, that the combination is forbidden in ordinary clothing.⁶

Kabbalists see deep spiritual meaning in the structure of the High Priest’s belt. In Kabbalistic thought, materials that embody different creative forces, like linen and wool, need to be kept apart in the physical world. But when the High Priest carries out holy duties in the Temple, the service puts the High Priest in God’s presence, and before the unity of God’s presence the differences among the forces disappear.

In a later post, I’ll discuss why the tallit is theoretically another exception to the rule of shatnez but that in modern practice also turns out to be subject to the prohibition against combining wool and linen.

Update: Cain and Abel’s sacrifices have been corrected, with thanks to Katarina, who pointed out that they were reversed in the original post.

References and Notes
¹Pirkey Rabbi Eliezer 21; Midrash Tanhuma B’reishit 9, Chizzkuni.
²Aryeh Kaplan, The Living Torah : The Five Books of Moses and the Haftarot, 602, note 19:19.
³Midrash Tanhuma B’reishit.
⁴Sefer HaMitzvot, Negative 30.
⁵If you want to dig into this more, take a look at Wikipedia’s Tetzaveh entry and take a listen to Tetzaveh – Heaven’s Girdle on Chabad.org (If you’re at work, note that the audio starts automatically when the page loads).
⁶Kaplan, The Living Torah : The Five Books of Moses and the Haftarot, 973, note 22:11.

Related Sources
In addition to the sources mentioned in the post, here are articles worth taking a look at:
– The Mitzvah of Shatnez (Star-K.org)
– Wool and Linen = Shatnez (Aish.com)

(Top Image: 1) Wildlife and Plants of Israel by Lehava Center Nazaret via Wikimedia Commons and the PikiWiki – Israel Free Image Collection Project; 2) Use of Flax for Fibre/ Linnen: Flax Straw, Yarn and Rope by Florian Gerlach (Nawaro) via Wikimedia Commons | Painting Image: Abel’s Soul Ascends to Heaven by Antonio Balestra, De Agostini Picture Library / A. Dagli Orti via Wikimedia Commons)

Maria Bywater is the author of Sew Jewish, available from Amazon.com and in PDF format from Etsy.