“Contrary to what I have heard said, it is perfectly possible to understand a text without knowing whether it is E or whatever. If I insist on a documentary setting, or an historical setting in which the text was composed, I am often, even usually, tied to pure hypothesis: the connection with a source is dubious, the existence of the source (E) is in question. In any case the historical setting of the passage’s composition is largely a guess. And still the text itself in its most important setting, its actual place in scripture, lies before me to study as a grammatical and literary structure that I can analyze with some confidence without beginning with a chancy guess about origins.”
-D.J. McCarthy, “Exodus 3:14: History, Philology and Theology,” CBQ 40 (1978).