Book of Deuteronomy have given various answers to the problem. The Deuteronomistic history theory is currently the most popular (Deuteronomy was originally just the law code and covenant, written to cement the religious reforms of Josiah, and later expanded to stand as the introduction to the full history); but there is an older theory which sees Deuteronomy as belonging to Numbers, and Joshua as a sort of supplement to it. This idea still has supporters, but the mainstream understanding is that Deuteronomy, after becoming the introduction to the history, was later detached from it and included with Genesis-Exodus-Leviticus-Numbers because it already had Moses
Book of Leviticus Book of Leviticus The Book of Leviticus () is the third book of the Torah and of the Old Testament. Most of its chapters (1–7, 11–27) consist of God's speeches to Moses, in which he is commanded to repeat to the Israelites. This takes place within the story of the Israelites' Exodus after they escaped Egypt and reached Mt. Sinai (Exodus 19:1). The Book of Exodus narrates how Moses led the Israelites in building the Tabernacle (Exodus 35–40) based on God's instructions (Exodus 25–31). Then in Leviticus, God tells the Israelites and their priests how to make offerings in the