Lehi undoubtedly named his son Joseph after Joseph of Egypt. In this part of his blessings and discourses, he uses that name to bring up the prophecies of Joseph of Egypt. Lehi specifically notes that he, and therefore all his family, are descendants of Joseph of Egypt. That tie allows Lehi to speak of prophecies from Joseph of Egypt. These prophecies must have been contained on the plates of brass, as we do not have them in our current Old Testament.
Lehi declares that Joseph of Egypt had a vision of the future, and that vision included Lehi’s time. Joseph of Egypt had prophesied that some of his descendants would be a righteous branch of Israel, but broken off. Jacob will provide an elaborate allegory of the olive tree, but in 1 Nephi 10:12 we saw that Lehi had earlier compared Israel to an “olive tree, whose branches should be broken off and should be scattered upon all the face of the earth.” Although Jacob quotes Zenos as his source, Lehi is either suggesting that Joseph of Egypt knew the allegory, or that Lehi had likened the prophecy of Joseph of Egypt to that allegory.
Lehi also appears to suggest that in addition to his prophecy that the Messiah would come six hundred years from the time they left Jerusalem, that the Messiah would be made manifest to his seed. Christ’s physical appearance to the remnant of the righteous in Bountiful fulfilled this prophecy. While there is every indication that the Nephites understood that the Messiah would be born and would die, there is less indication that they knew that he would personally appear. If they remembered this prophesy, they did not understand the nature of how “the Messiah would be manifest unto them in the latter days.”