He prohibited us from wearing a garment woven of wool and linen, like that which would be worn by the idolatrous priests at that time. And that is His saying, "You shall not wear shatnez" (Deuteronomy 13:18). And this [practice] is famous today among the idolatrous priests in Egypt. And one who transgresses this negative commandment is liable for lashes. And the regulations of this commandment have already been explained in Tractate Kilayim, Shabbat, Sotah and Makkot. (See Parashat Ki Tetzei; Mishneh Torah, Foreign Worship and Customs of the Nations 10.)