Despite the use of pre-Mosaic sources and indications of post-Mosaic glosses and elaborations, internal and external evidence affirms
the essential Mosaic authorship of the Pentateuch.
As receiver and transmitter of divine revelation, and teacher of God's laws and decrees to the nation of Israel,
Moses' original written word was equivalent to the inerrant Word of God.
From the Exodus to the Conquest,
Mosaic prophecies were fulfilled and authenticated the supernatural nature of the Pentateuch.