Purifications or Baptisms of High Priest on Day of Atonement
Source: TTT
Leviticus 16:4, 24
He is to wear the sacred linen tunic, with linen undergarments. He must tie a linen sash around him and put on the linen turban. These are holy garments, and he must bathe himself with water before he wears them. / He is to bathe himself with water in a holy place and put on his own clothes. Then he must go out and sacrifice his burnt offering and the people’s burnt offering to make atonement for himself and for the people.