Lehi finishes quoting Joseph of Egypt at this point (v. 22), and returns to the blessing of his son, Joseph. This is important to know because Lehi is prophesying about his own son, not Joseph Smith. He prophesies that Joseph’s posterity will not be destroyed, for they shall hearken to the Book of Mormon (v. 23). Since the Book of Mormon was not available until 1830, Lehi must have meant that they would be preserved. In his foreknowledge the Lord knew they would hearken when the Book of Mormon became available. He then prophesied that one among his son Joseph’s seed would do much good and bring to pass much restoration to the house of Israel, and to the seed of his brethren (v. 24). Joseph Smith brought forth the Book of Mormon, and the one among them (Joseph’s, son of Lehi, seed) was to hearken to the book brought forth. Therefore it is difficult to relate the prophecy to Joseph Smith. Joseph Smith’s work was to bring Joseph of Egypt’s seed “out of darkness unto light,” and “the one mighty among them was to bring them “out of captivity unto freedom” (2 Nephi 3:5). The interpretation of there being two separate persons has been given by modern day apostles. President Joseph Fielding Smith taught that “father Lehi made one promise to his son Joseph and that was that from his seed would arise one who should” fulfill 2 Nephi 24, and then he added:
That the remnants of Joseph, found among the descendants of Lehi, will have part in this great work is certainly consistent, and the great work of the restoration the building of the temple and the city of Zion, or New Jerusalem, will fall to the lot of the descendants of Joseph, but it is Ephraim who will stand at the head and direct the work.
Elder Spencer W. Kimball declared:
The Lamanite must rise in majesty and power … And in the day when their prophet shall come, one shall rise … mighty among them … being an instrument in the hands of God, with exceeding faith, to work mighty wonders … (2 Nephi 3:24). When the time is right, the lord will raise him up. [CR, Oct. 1947, 22]
Lehi’s final admonition to his youngest son Joseph is the last recorded words of the old patriarch who led the families of Joseph out of Jerusalem. His mission is now completed and he awaited his death.