The Documentary Hypothesis, which in the 20th century was the standard theory to explain the development of the Pentateuch, has been challenged from different angles. One important text corpus where new proposals have been brought into the debate is the Book of Numbers. The articles in this volume address the formation of the Book of Numbers from the earliest to the latest strata. They focus on topics like the source-critical placement of the texts in Deuteronomy that retell events from Numbers, the status of the late priestly halakhic legal adaptations and their relation to the books of Leviticus and Deuteronomy, the search for the redactor(s) who combined the Priestly and the non-priestly material, the relation to the Book of Joshua, and the status of the very late additions that formed the Pentateuch as Torah for the community. Thus, the volume contributes to the discussion on the normative background and identity formation in the late Persian period. Special attention is also given to the composition of the final text of the Book of Numbers and its understanding of law and narrative. The authors, among them outstanding researchers in the field, partially contributed to a symposium on the topic Torah in the Book of Numbers at the Ruhr-Universitat Bochum, held on April 12-13, 2011.