Manasseh was the elder son of Joseph, who was sold into Egypt, and Asenath, and the head of one of the twelve tribes of Israel. Lehi’s line is traced back to him: Aminadi was a descendant of Nephi, son of Lehi, who came out of Jerusalem and was a descendant of Manasseh, son of Joseph (Alma 10:3). Lehi himself, reading the genealogy on the plates of brass, found that he was a descendant of Joseph who was sold into Egypt (1 Nephi 5:14).
When Jacob, near death, blessed Joseph’s two sons, Manasseh was the firstborn, but Jacob laid his right hand on the younger Ephraim and his left on Manasseh, and set Ephraim before Manasseh; he blessed both to grow into a multitude, saying Manasseh would become a people and be great while Ephraim’s seed would become a multitude of nations (Genesis 48:1-20). The Genesis blessing on Joseph called him “a fruitful bough, even a fruitful bough by a well; whose branches run over the wall” (Genesis 49:22).
In Nephi’s quotation of Isaiah, Manasseh and Ephraim are paired against each other and together against Judah: “Manasseh, Ephraim; and Ephraim, Manasseh; they together shall be against Judah. For all this his anger is not turned away, but his hand is stretched out still” (2 Nephi 19:21). The same refrain — “For all this his anger is not turned away, but his hand is stretched out still” — closes an earlier passage on the Lord’s anger against his people (2 Nephi 15:25).
In Moses’ blessing on Joseph, the horns by which the people are pushed to the ends of the earth are “the ten thousands of Ephraim” and “the thousands of Manasseh” (Deuteronomy 33:17). The record of Lehi’s descendants is identified with the “stick of Joseph,” to be joined with the stick of Judah (Ezekiel 37:15-19), the writing of the fruit of Joseph’s loins growing together with the writing of Judah (2 Nephi 3:12), the record of the stick of Ephraim whose keys were committed to Moroni (Doctrine and Covenants 27:5).