Leviticus 21:21-25

No man that hath a blemish of the seed of Aaron the priest shall come nigh to offer the offerings of the LORD made by fire: he hath a blemish; he shall not come nigh to offer the bread of his God.

He shall eat the bread of his God, both of the most holy, and of the holy.

Only he shall not go in unto the vail, nor come nigh unto the altar, because he hath a blemish; that he profane not my sanctuaries: for I the LORD do sanctify them.

And Moses told it unto Aaron, and to his sons, and unto all the children of Israel.