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 12

12:4 And she shall then continue in the blood of her purifying three and thirty days; she shall touch no hallowed thing, nor come into the sanctuary, until the days of her purifying be fulfilled.