Leviticus 21:1-5 NIV

[1] The LORD said to Moses, “Speak to the priests, the sons of Aaron, and say to them: ‘A priest must not make himself ceremonially unclean for any of his people who die, [2] except for a close relative, such as his mother or father, his son or daughter, his brother, [3] or an unmarried sister who is dependent on him since she has no husband—for her he may make himself unclean. [4] He must not make himself unclean for people related to him by marriage, and so defile himself. [5] “ ‘Priests must not shave their heads or shave off the edges of their beards or cut their bodies.