Nephi introduces his record by recounting the manner in which the Lord called his father to prophesy to the inhabitants of Jerusalem. His doing so establishes that his father's call as a prophet was legitimate, that his authority and message can be traced directly to God. This was particularly important because false prophets were much in evidence in Judah. Moreover the pattern of direct approach by the Lord to his prophet was so well established (virtually every prophetic book in the Old Testament opens with some such expression as “The word of the Lord came to . . .”) that to any listener of that day such a declaration from a professed prophet was essential to the establishment of his credibility.
“Moses Was Commanded of the Lord”
In relating the narrative of Israel's redemption from Egypt and their wilderness wanderings, Nephi confirmed the historical veracity of these events as contained in the Bible. Here one prophet testified of the works of another. Moses in reality parted the Red Sea, brought forth water from a rock, and fed the children of Israel in a miraculous manner.