The original Hebrew title of this third book of the law is taken from the first word, translated “And He called.” Several OT books derive their Hebrew names in the same manner (e.g., Genesis, “In the beginning”; Exodus, “Now these are the names”). The title “Leviticus” comes from the Latin Vulgate version of the Greek OT (LXX)1 Leuitikon meaning “matters of the Levites” (25:32, 33). While the book addresses issues of the Levites’ responsibilities, much more significantly, all the priests are instructed in how they are to assist the people in worship, and the people are informed about how to live a holy life. New Testament writers quote the book of Leviticus over 15 times.
Before the year that Israel camped at Mt. Sinai: 1) the presence of God’s glory had never formally resided among the Israelites; 2) a central place of worship, like the tabernacle, had never existed; 3) a structured and regulated set of sacrifices and feasts had not been given; and 4) a High-Priest, a formal priesthood, and a cadre of tabernacle workers had not been appointed. As Exodus concluded, features one and two had been accomplished, thereby requiring that elements three and four be inaugurated, which is where Leviticus fits in. Exodus 19:6 called Israel to be “a kingdom of priests and a holy nation.” Leviticus in turn is God’s instruction for His newly redeemed people, teaching them how to worship and obey Him.

Israel had, up to that point, only the historical records of the patriarchs from which to gain their knowledge of how to worship and live before their God. Having been slaves for centuries in Egypt, the land of a seemingly infinite number of gods, their concept of worship and the godly life was severely distorted. Their tendency to hold on to polytheism and pagan ritual is witnessed in the wilderness wanderings, e.g., when they worshiped the golden calf (cf. Ex. 32). God would not permit them to worship in the ways of their Egyptian neighbors, nor would He tolerate Egyptian ideas about morality and sin. With the instructions in Leviticus, the priests could lead Israel in worship appropriate to the Lord. 

Even though the book contains a great deal of law, it is presented in a historical format. Immediately after Moses supervised the construction of the tabernacle, God came in glory to dwell there; this marked the close of the book of Exodus (40:34–38). Leviticus begins with God calling Moses from the tabernacle and ends with God’s commands to Moses in the form of binding legislation. Israel’s King had occupied His palace (the tabernacle), instituted His law, and declared Himself a covenant partner with His subjects.

No geographical movement occurs in this book. The people of Israel stay at the foot of Sinai, the mountain where God came down to give His law (25:1; 26:46; 27:34). They were still there one month later when the record of Numbers began (cf. Num. 1:1).