Leviticus can also be called “The Book of the Law of the Priests” as it contains very little historical matter, concerning itself with priestly legislation and the practice of the Law among the people. Much importance is placed upon Israel’s separation from all heathen influences so that the nation may retain its religious purity.

Leviticus 2

2:10 And that which is left of the meat offering shall be Aaron's and his sons': it is a thing most holy of the offerings of the LORD made by fire.