Leviticus 21:4-6

Amplified Bible

⁴ He shall not become unclean as a relative by marriage among his people, and so profane himself. ⁵ The priests ^[a]shall not shave their heads, nor shave off the edges of their beards, nor make any cuts in their body. ⁶ They shall be holy to their God and not profane the name of their God; for they present the offerings by fire to the Lord, the food of their God; so they shall be holy.