Carol A. Redmount, “Bitter Lives: Israel in and out of Egypt,” in The Oxford History of the Biblical World, Michael D. Coogan, editor (Oxford: Oxford University Press, 1998), 70-71.
The biblical account makes an exceptionally poor primary historical source for the Exodus events. Possible historical data are mostly inconsistent, ambiguous, or vague. No Egyptian pharaoh associated with the Exodus events is named. When the king of Arad fights the Israelites in Numbers 21.1, he is merely called “the Canaanite, the king of Arad.” In those few places where the Exodus narrative is meticulous about detail, the particulars are unhelpful – such as the stages in the trek out of Egypt, or he names of the three Transjordanian rulers (King Sihon of the Amorites in Num. 1.21; King Og of Bashan in Num. 21.33; Balak, son of Zippor, king of Moab, in Num. 22.4) who are completely unknown outside the Bible – or inappropriate. In the latter case, biblical precision generally stems from concerns other than historical: standardized generation formulas grounded in symbolic numbers are applied backward to calculate the year of the Exodus; or historically impossible numbers are given for participants in the departure from Egypt to stress the event’s significance.
The surviving biblical account of the Exodus has thus been shaped by later creative hands responding to overarching theological agendas and differing historical and cultural circumstances. Many of the preserved details are anachronistic, reflecting conditions during the first millennium BCE when the narrative was written down and repeatedly revised. As a consequence the final Exodus account should not be accepted at face value, nor can it function as an independent historical variable against which other sources of historical information are judged. Rather, it is a dependent variable whose historical value is judged by and against other, more reliable sources of historical information.