Exodus 28:41-43

New Revised Standard Version, Anglicised Catholic Edition

⁴¹ You shall put them on your brother Aaron, and on his sons with him, and shall anoint them and ordain them and consecrate them, so that they may serve me as priests. ⁴² You shall make for them linen undergarments to cover their naked flesh; they shall reach from the hips to the thighs; ⁴³ Aaron and his sons shall wear them when they go into the tent of meeting, or when they come near the altar to minister in the holy place; or they will bring guilt on themselves and die. This shall be a perpetual ordinance for him and for his descendants after him.