Ezekiel 44:17-18

17And it shall be that when they enter at the gates of the inner courtyard, they shall be clothed with 1linen garments; and wool shall not 2be worn by them while they are ministering in the gates of the inner courtyard or in the house.

18Linen 3turbans shall be on their heads and 4linen undergarments shall be around their waists; they shall not put on anything that makes them sweat.