In this prophecy Lehi quotes only several small parts of the much longer text of words spoken to Joseph by Jacob found in the Joseph Smith Translation of Genesis 48:7–11, and also containing words spoken by Joseph to his brothers in JST Genesis 50:24–38.
For example, Lehi said that "the Lord God would raise up a righteous branch unto the house of Israel; not the Messiah, but a branch that would be broken off" (3 Nephi 5:5). This tracks the ancient prophecy in JST Genesis 50:24 that "the Lord God will raise up a righteous branch out of my loins … (not the Messiah)."
Lehi spoke of "a choice seer" that would be raised up "out of the fruit of [the] loins" of Joseph of old (3 Nephi 3:7). The version in JST Genesis 50:27 used the words "a choice seer" who will be "raise[d] up out of the fruit of thy loins."
Lehi promised his son Joseph that this seer would be called Joseph "after the name of his father" (2 Nephi 3:15). That prophecy to which Lehi was referring is now found in JST Genesis 50:33, "and his name shall be called Joseph, and it shall be after the name of his father."
And Lehi said, "Thus prophesied Joseph: I am sure of this thing, … for the Lord hath said unto me, I will preserve thy seed forever" (2 Nephi 3:16). In the longer JST version, the text assures that "the Lord sware unto Joseph that he would preserve his seed forever" (JST Genesis 50:34).
Book of Mormon Central, "How Lehi Likened the Scriptures to Himself (2 Nephi 3:18)," KnoWhy 418 (March 22, 2018). "Most of what Lehi quoted to his son is similar to the Joseph Smith Translation of Genesis 50:24–38. However, the differences between the Joseph Smith Translation and Lehi’s blessing in the Book of Mormon show how Lehi specifically applied the scriptures to the lives of his descendants."