Leviticus 22:3-6

Say to them: If any man from any of your descendants throughout your generations is in a state of uncleanness yet approaches the holy offerings that the Israelites consecrate to the LORD, that person will be cut off from my presence; I am the LORD. No man of Aaron’s descendants who has a skin disease  or a discharge is to eat from the holy offerings until he is clean. Whoever touches anything made unclean by a dead person or by a man who has an emission of semen, or whoever touches any swarming creature that makes him unclean or any person who makes him unclean — whatever his uncleanness —  the man who touches any of these will remain unclean until evening  and is not to eat from the holy offerings unless he has bathed his body with water.