Lehi and his seed are not the only branch to be grafted into the olive tree. All of the branches of the house of Israel will be grafted in. The allegory of Zenos speaks of three natural branches: “the first and the second and also the last” (Jacob 5:39). Nephi spoke to his brothers of one of the two other natural branches, “the restoration of the Jews in the latter days” (v. 19). He not only recorded their general destiny, but also gave the source of his comments, “the words of Isaiah.” The other branch, the lost tribes, will be identified and both of these branches will be discussed more fully when the Book of Mormon text refers to them. The covenant made to Abraham will be fulfilled in the latter days through the grafting in of the natural branches and in the offering of the blessings of the gospel to all nations as Abraham was promised (v. 18). Mormon gave a second witness to the fulfillment of Abraham’s covenant being in the latter days:
And behold, the Lord hath reserved their blessings, which they might have received in the land, for the Gentiles who shall possess the land.
But behold, it shall come to pass that they shall be driven and scattered by the Gentiles; and after they have been driven and scattered by the Gentiles, behold, then will the Lord remember the covenant which he made unto Abraham and unto all the house of Israel.
And also the Lord will remember the prayers of the righteous, which have been put up unto him for them. [Mormon 5:19–21]
Nephi’s interpretive comments caused his brothers to ask further questions.