Leviticus 22:1-9

And the LORD spake unto Moses, saying, Speak unto Aaron and to his sons, that they separate themselves from the holy things of the children of Israel, and that they profane not my holy name in those things which they hallow unto me: I am the LORD. Say unto them, Whosoever he be of all your seed among your generations, that goeth unto the holy things, which the children of Israel hallow unto the LORD, having his uncleanness upon him, that soul shall be cut off from my presence: I am the LORD. What man soever of the seed of Aaron is a leper, or hath a running issue; he shall not eat of the holy things, until he be clean. And whoso toucheth any thing that is unclean by the dead, or a man whose seed goeth from him; or whosoever toucheth any creeping thing, whereby he may be made unclean, or a man of whom he may take uncleanness, whatsoever uncleanness he hath; the soul which hath touched any such shall be unclean until even, and shall not eat of the holy things, unless he wash his flesh with water. And when the sun is down, he shall be clean, and shall afterward eat of the holy things; because it is his food. That which dieth of itself, or is torn with beasts, he shall not eat to defile himself therewith: I am the LORD. They shall therefore keep mine ordinance, lest they bear sin for it, and die therefore, if they profane it: I the LORD do sanctify them.