Jewish Law
The Torah Prohibition of Shaatnez: Why Wool and Linen Must Never Be Mixed
Discover the ancient commandment that forbids blending wool and linen — its deep spiritual meaning, halachic details, and the blessings promised to those who guard it
ShatnezThe prohibition of Shaatnez forbids wearing any garment that contains wool and linen woven together into one fabric. This is a Torah prohibition — one of the Issurei Kilayim (forbidden mixtures).
The Torah states: “You shall not wear a garment of mixed fabric, wool and linen together” (Devarim 22:11). And in Vayikra 19:19:
“You shall not wear a garment of mingled kinds.”
The Mishnah in Kilayim teaches that one who violates this law “perverts the will of his Father in Heaven.” Maimonides (the Rambam) explains: “He turns away from truth and distances the mercy of God from himself, transgressing a divine command for no personal pleasure — and this is a grave sin.”
The Meaning of “Shaatnez”
According to the Sages, the word Shaatnez is an acronym of shua, tavui, v’nuz — “combed, spun, and woven together.” In Kabbalistic tradition, it is also read as “Satan az” — “a fierce or destructive force.”
Biblical Sources
Shaatnez appears twice in the Torah:
In Vayikra 19:19 — alongside other forms of forbidden mixtures.
In Devarim 22:11 — clarifying that it specifically refers to wool and linen together.
What Is Prohibited?
According to the Sages, the prohibition applies only when wool and linen are actually woven or sewn together. Simply wearing raw wool and flax fibers side by side is not forbidden.
Modern Applications
The prohibition applies not only to clothing but also to household items that come into regular contact with the body:
Suits, coats, shirts, pants, scarves, hats, and ties
Upholstery, cushions, mattresses, blankets, and bedding
Under civil law, manufacturers are not required to list fibers under 5% of a garment’s content — but halachically, even a single thread of linen in a wool garment is forbidden. Therefore, one must not rely on clothing labels.
Testing for Shaatnez
Today there are special laboratories that test garments for Shaatnez. Expert inspectors who are observant Jews trained in textile analysis, use microscopes to identify even minute traces of linen or wool.
Why Is It Forbidden?
The Sages describe this as a “divine decree” (gezerat melech) — a command whose full reason is known only to God. The Rambam suggests that idolaters once wore garments of wool and linen mixtures as part of their rituals, and the Torah therefore prohibited this to distance Israel from pagan customs.
Spiritual and Physical Effects
Kabbalistic sources describe Shaatnez as causing spiritual disharmony, blocking divine flow and peace. Some traditions even associate it with physical imbalance or discomfort, symbolizing a disruption of the natural order God created.
The Reward for Avoiding Shaatnez
The Chochmat Adam promises: “Whoever is careful not to wear Shaatnez will merit to wear garments of salvation and a cloak of righteousness.”
The Pnei Zaken adds: “One who guards himself from forbidden mixtures will live long in this world and the next, will not return in reincarnation, and will merit righteous children and every blessing.”
The Zohar HaKadosh teaches: “Whoever refrains from wearing wool and linen together brings peace to himself and to the entire world and gives life to creation.”
The Severity of the Transgression
One who wears a Shaatnez garment violates a Torah commandment every single moment it is worn. According to the Derushei Tzelach, even wearing Shaatnez for one day can spiritually dull a person — “his prayer is not accepted for forty days.”
