Leviticus (Va’yikra in Hebrew) means “and He called”, which is how verse one starts. We call this book Leviticus because it records the duties of the Levites. The Hebrew title is representative of the content and purpose of the book, namely the calling of God’s people, and in particular the calling of the Levites, to minister before Him.
This book was written by Moses and its major themes are like an instruction manual for morals and ethics. There are civil, sanitary, ceremonial, moral and religious regulations for the nation of Israel. There are also instructions for making offerings (burnt, meat, peace, sin, trespass, grain). We have the ordination of Aaron and his son, rules and laws for purification, regulations for atonement, rules for sexual relationships, provisions for festivals, and final instructions and warnings.