Leviticus (lĬvĬt´ekes) is the third book of the Hebrew Scriptures. It is believed to have been written by Moses betwee 1440 and 1400 BC, but this authorship continues to be a source of debate between liberal and conservative scholars. Note that in the 27 chapters of Leviticus, there are 56 references to Moses' authorship (e.g., 1:1; 4:1; 6:1, 24; 8:1). Leviticus probably reached its final canonical shape by about the year 400 BC.
Moses also wrote Genesis, Exodus, Numbers, and Deuteronomy--the other four books of the "Pentateuch" (pente meaning "five" and teuchos meaning "volumes" in Greek). The Pentateuch is the name given to the Five Books of Moses, which are the first five books of the Hebrew Scriptures. The first five books are also known as the "Books of the Law" and the "Torah" (instruction in the Hebrew).
What is interesting about Leviticus is that it was specifically written for the tribe of Levi.The word itself means "of the Levites". The Levites were the designated priests of the people of Israel. Yet there is a tendency to use Leviticus more broadly to society, which doesn't make much sense if the book was specifically written for a group of people who had the very unique job of carrying out sacrificial offerings to God.
For example, V'et zachar lo tishkav mishk'vey eeshah toeyvah hee means "And with a male you shall not lay lyings of a woman". This is taken from Leviticus 18:22, which is part of the so-called "Holiness Code".