Leviticus 21:10

“Then you shall take the anointing oil and pour it on his head and anoint him.

Then he poured some of the anointing oil on Aaron’s head and anointed him, to set him apart as holy.

Then Moses said to Aaron and to his sons Eleazar and Ithamar, “Do not uncover your heads nor tear your clothes, so that you will not die and that He will not become wrathful against all the congregation. But your relatives, the whole house of Israel, shall weep over the burning which Yahweh has brought about.

“Groan silently; make no mourning for the dead. Bind on your headdress and put your shoes on your feet and do not cover your mustache and do not eat the bread of men.”