Leviticus 22:1-9

Then the LORD spoke to Moses, saying, “Speak to Aaron and his sons, that they separate themselves from the holy things of the children of Israel, and that they do not profane My holy name by what they dedicate to Me: I am the LORD. Say to them: ‘Whoever of all your descendants throughout your generations, who goes near the holy things which the children of Israel dedicate to the LORD, while he has uncleanness upon him, that person shall be cut off from My presence: I am the LORD. ‘Whatever man of the descendants of Aaron, who is a leper or has a discharge, shall not eat the holy offerings until he is clean. And whoever touches anything made unclean by a corpse, or a man who has had an emission of semen, or whoever touches any creeping thing by which he would be made unclean, or any person by whom he would become unclean, whatever his uncleanness may be— the person who has touched any such thing shall be unclean until evening, and shall not eat the holy offerings unless he washes his body with water. And when the sun goes down he shall be clean; and afterward he may eat the holy offerings, because it is his food. Whatever dies naturally or is torn by beasts he shall not eat, to defile himself with it: I am the LORD. ‘They shall therefore keep My ordinance, lest they bear sin for it and die thereby, if they profane it: I the LORD sanctify them.