Leviticus 21:1, 11
Leviticus 21:1 ESV
And the LORD said to Moses, “Speak to the priests, the sons of Aaron, and say to them, No one shall make himself unclean for the dead among his people
Leviticus 21:11 ESV
He shall not go in to any dead bodies nor make himself unclean, even for his father or for his mother.