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 22

22:25 Neither from a stranger's hand shall ye offer the bread of your God of any of these; because their corruption is in them, and blemishes be in them: they shall not be accepted for you.