Leviticus documents the law of the priests. The sacrifices described foreshadow the coming of Christ. Animal sacrifices were required to be without blemish. Burnt offerings were a pleasing aroma to the Lord when offered according to His instructions. God required grain offerings to be presented to Aaron’s sons, and a portion was burned as a memorial on the altar as a pleasing aroma to the Lord. The remaining grain was food for Aaron and his sons. Any baked offering was to be unleavened. Purity was a necessity in all sacrifices to the Lord.