Leviticus 22:4-5

41No man of the 2descendants of Aaron, who has 3leprosy or has a discharge, may eat of the holy gifts until he is clean. 4And one who touches anything made unclean by a corpse, or 5a man who has a seminal emission,

5or 6a man who touches any swarming things by which he is made unclean, or touches any person by whom he is made unclean, whatever his uncleanness;