The incorporation of... earlier sources does not mean that the Pentateuch or Former Prophets is the work of an editor who pasted together various docuements. Once we view the work as a whole, we see that it is a fresh creation though not a creatio ex nihilo. The same holds for Homeric Epic that has been subjected to the same kinds of modern literary criticism.

Ch.VIII Further Observations on the Bible - The Common Background of Greek and Hebrew Civilizations (1965 [1962])