Exodus 28:36

28:36 “You are to make a plate of pure gold and engrave on it the way a seal is engraved: “Holiness to the Lord.”

Leviticus 21:6-8

21:6 “‘They must be holy to their God, and they must not profane the name of their God, because they are the ones who present the Lord’s gifts, the food of their God. Therefore they must be holy. 21:7 They must not take a wife defiled by prostitution, nor are they to take a wife divorced from her husband, for the priest is holy to his God. 21:8 You must sanctify him because he presents the food of your God. He must be holy to you because I, the Lord who sanctifies you all, am holy.

Leviticus 21:10-12

Rules for the High Priest

21:10 “‘The high priest – who is greater than his brothers, on whose head the anointing oil is poured, who has been ordained to wear the priestly garments – must neither dishevel the hair of his head nor tear his garments. 21:11 He must not go where there is any dead person; he must not defile himself even for his father and his mother. 21:12 He must not go out from the sanctuary and must not profane the sanctuary of his God, because the dedication of the anointing oil of his God is on him. I am the Lord.

Numbers 16:7

16:7 put fire in them, and set incense on them before the Lord tomorrow, and the man whom the Lord chooses will be holy. You take too much upon yourselves, you sons of Levi!”