Leviticus 16:2-4

The Voice

Eternal One (to Moses): ² Go, talk to Aaron, and warn him that he cannot go whenever he wants beyond the veil to the holy place before the seat of mercy that covers the covenant chest. If he does, he will lose his life because I will appear in the cloud above the seat of mercy. ³ Instead, he may enter into the holy place with a bull from the herd for the purification offering for sin and a ram for the burnt offering. ⁴ Aaron will wash himself with water and then put on his sacred garments: the linen underclothes and the sacred linen tunic. He will tie the linen sash around his waist and put on his linen turban.