Complex sentence: Kaufmann regards the non-prophetic parts of scripture as reflecting an earlier stage of the Israelite religion, and--in opposition to Wellhausen and others--claims that the P-source significantly predates the Babylonian exile and Deuteronomy.
Split into simpler sentences: Kaufmann regards the non-prophetic parts of scripture as reflecting an earlier stage of the Israelite religion. While he accepts the existence of the three primary sources JE, P, and D, he claims--in opposition to Wellhausen and others--that the P-source significantly predates the Babylonian exile and Deuteronomy.