No man of the descendants of Aaron who is a leper or has a discharge may eat the holy things [the offerings and the showbread] until he is clean. And whoever touches any person or thing made unclean by contact with a corpse or a man who has had a seminal emission,

“Then you shall take fine flour and bake twelve cakes (bread of the Presence, showbread) with it; two-tenths of an ephah shall be in each cake (loaf).

Every Sabbath day Aaron shall arrange the showbread before the Lord continually; it is an everlasting covenant for the Israelites.