Jehovah speaks through his prophets, and in these verses the prophet becomes an unnamed surrogate for Jehovah. Thus, Jehovah says that he has called the prophet “to declare,” and that should Israel listen to him, “he shall make his way prosperous.” The very presence of the idea that following the prophet would make the people prosperous clearly resonates with the Nephite foundational promise that they would prosper upon their righteousness.
Just as the prophet was sent to Israel to teach them how to profit, or to prosper, so too will the Nephites prosper as they follow their prophet-leader.
The emphasis on the seed becoming as the sand also resonated with the new Nephite nation. Nephi would have seen Isaiah as setting the foundational principles upon which the promise of the new land would be based.