Book of Numbers twelve princes, one of each tribe. The majority of modern biblical scholars believe that the Torah (the books of Genesis, Exodus, Leviticus, Numbers, and Deuteronomy) reached its present form in the post-Exilic period (i.e., after c.520 BCE), based on pre-existing written and oral traditions and "contemporary geographical and demographic details but even more importantly from contemporary political realities". The five books are often described as being drawn from four "sources" - schools of writers rather than individuals - the Yahwist and the Elohist (frequently treated as a single source), the Priestly source and the Deuteronomist. There is ongoing dispute over
On the Reliability of the Old Testament the Old Testament. The book opens with an introductory chapter surveying the history with which it intends to deal, the continuous narrative in the Hebrew Bible from the Genesis creation narrative to the return of the Jews to Jerusalem from the Babylonian captivity in the early days of the Persian Empire in the 5th century BC. The author claims that this history was written at the same time as the events it describes in its various sections, and that this can be confirmed by comparing the Old Testament with non-Biblical sources, both written and archaeological. He clarifies by stating that