Leviticus 6:17-23

It shall not be baked with leaven [which represents corruption or sin]. I have given it as their share of My offerings by fire; it is most holy, like the sin offering and the guilt offering. Every male among the sons of Aaron may eat it [as his share]; it is a permanent ordinance throughout your generations, from offerings by fire to the LORD. Whatever touches them will become consecrated (ceremonially clean).’ ” Then the LORD spoke to Moses, saying, “This is the offering which Aaron and his sons are to present to the LORD on the day when he is anointed: the tenth of an ephah of fine flour as a regular grain offering, half of it in the morning and half of it in the evening. It shall be prepared with oil on a griddle. When it is well stirred, you shall bring it. You shall present the grain offering in baked pieces as a sweet and soothing aroma to the LORD. The priest from among the sons of Aaron who is anointed in his place shall offer it. By a permanent statute it shall be entirely offered up in smoke to the LORD. So every grain offering of the priest shall be burned entirely. It shall not be eaten.”