Sailhamer, John H. The Pentateuch As Narrative Grand Rapids: Zondervan, 1992.
Introduction, “Interpreting the Pentateuch” pp. 1-79
Part E, “Authorship and Sources” pp. 23-25
The Pentateuch is formally anonymous, though uniformly ascribed to Moses by later authors. Much scholarship has focused on sources of information used in composition. Sailhamer observes that “the Pentateuch depicts accurately the age and historical period of the patriarchs and the Exodus, which is a period about which our knowledge has considerably increased in modern times from archaeological discoveries” (Sailhamer 1992, 23). Sailhamer looks for documentary evidence. Yet he seems to think evidence is not lost. “In the case of the patriarchs, Moses or someone later than him would not have known such details” (Ibid., 24). This may be a weak argument as it discounts the credibility of oral tradition.
“The Pentateuch is characterized by both an easily discernable unity and a noticeable lack of uniformity” (Ibid., 24). The text shows signs of drawing on a variety of sources which are tied together by devices such as genealogies. We would not expect a lot of uniformity as the author would likely keep the sources recognizable. Yet the message has considerable unity.