Exodus 28:42-43

Amplified Bible, Classic Edition

⁴² You shall make for them [white] linen trunks to cover their naked flesh, reaching from the waist to the thighs.

⁴³ And they shall be on Aaron and his sons when they go into the Tent of Meeting or when they come near to the altar to minister in the Holy Place, lest they bring iniquity upon themselves and die; it shall be a statute forever to Aaron and to his descendants after him.