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 20

20:23 And ye shall not walk in the manners of the nation, which I cast out before you: for they committed all these things, and therefore I abhorred them.