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 Genesis Book of Genesis The Book of Genesis (from the Latin Vulgate, in turn borrowed or transliterated from Greek "", meaning "Origin"; , ""Bərēšīṯ"", "In [the] beginning") is the first book of the Hebrew Bible (the Tanakh) and the Old Testament. It can be divided into two parts, the Primeval history (chapters 1–11) and the Ancestral history (chapters 12–50). The primeval history sets out the author's (or authors') concepts of the nature of the deity and of humankind's relationship with its maker: God creates a world which is good and fit for mankind, but when man corrupts it with sin God