Nephi provides the first instance that demonstrates that he was becoming a teacher over his brothers. This incident, as well as many he will record later, serves to demonstrate the fulfillment of the prophecy Yahweh delivered to Nephi, and which the angel had delivered to his brothers.
Again assuming Nephi’s scribal training, he would have been quite familiar with the stories of Israel’s history as recorded in scripture. He would have been familiar with using scripture to provide a course of action in the present. In this case, he is admonishing his brothers to action against a formidable foe.
Nephi chose the story of Moses. Laban has his fifty, but Moses was up against Pharaoh’s army. Yahweh provided two miracles. The waters opened and the children of Israel came through on dry land. Then they returned, and destroyed Pharaoh’s army. Lest the brothers miss the lesson, he declares: “Let us go up; the Lord is able to deliver us, even as our fathers, and to destroy Laban, even as the Egyptians.”
The story of the parting of the waters certainly provided a parallel to their situation in that they faced a powerful enemy. It is perhaps also a foreshadowing, for Moses’ people were saved when the enemy was killed. The brothers will be saved when Nephi kills Laban.