Leviticus, the third book in the Torah, is also called the book of atonement. It is a guide to worship and sacrifices practices for Hebrew priests and teaches the sons of Israel the principles of dietary health, physical cleanliness, and spiritual holiness. It was written in about 1440 B.C. during the time of the completion of the tabernacle. Its key truth is holiness, and its key verse, in 19:2, is "Speak to all the congregation of the children of Israel, and say to them: ‘You shall be holy, for I the LORD your God am holy."