Consistent with the “other books” that are to come forth that will fulfill his prediction, therefore (1 Nephi 13:39), Jesus goes on to say that “in the latter day shall the truth come unto Gentiles, that the fulness of these things shall be made known unto them” (3 Nephi 16:7; emphasis added). That “truth” and “fulness” allude to the greater account of Jesus’ words to Lehi’s descendants that appears on the large plates of Nephi (2 Nephi 28:30; 29:1–14; 3 Nephi 26:7, 11), not on the small plates from which the Book of Mormon is taken (Words of Mormon 1:3– 10). Nevertheless, that greater account of Jesus’ words is to be brought forth to the house of Israel “through the fulness of the Gentiles”—that is, through the descendants of Ephraim who had assimilated into the Gentiles (3 Nephi 16:4, 7; cf. Genesis 48:19; Hosea 7:8; Romans 11:25). Underlying all of God’s dealings with the Gentiles are “the mercies of the Father unto the Gentiles” (3 Nephi 16:9), they being “blessed . . . because of their belief in me” (3 Nephi 16:6).
As with Nephi’s and Jacob’s predictions that are based on the prophecies of Isaiah, the house of Israel’s gathering from the four directions of the earth that Jesus predicts follows after their coming to “a knowledge of me, their Redeemer” (3 Nephi 16:4–5; cf. 1 Nephi 22:11–12; 2 Nephi 6:11, 14; 10:7). Because the terms “know” and “knowledge” define a covenant relationship in biblical theology, the house of Israel’s gaining a knowledge of their Redeemer implies that they come to know him personally, not just know about him (cf. Isaiah 19:21; Matthew 25:1–12). Returning from dispersion in a new exodus (Isaiah 11:11–12, 15–16; 52:11–12), they are welcomed home by some who are already there: “In that day shall this song be sung in the land of Judah: ‘Our city is strong; salvation he has set up as walls and barricades! Open the gates to let in the nation righteous because it keeps faith!’ Those whose minds are steadfast, [O Jehovah,] you preserve in perfect peace, for in you they are secure” (Isaiah 26:1–3; cf. 12:1–6).
Jesus’ prediction that “in the latter day shall the truth come unto the Gentiles, that the fulness of these things shall be made known unto them” (3 Nephi 16:7; emphasis added) further infers that in the “latter day” or endtime the Mormon Gentiles are espousing less than the truth and fulness, relying instead on “precepts of men,” as noted (Isaiah 29:13; 2 Nephi 28:26, 31). In that connection, not only do the large plates of Nephi but also other records reveal “all things” and “the truth which is in the Lamb” (1 Nephi 14:26; emphasis added). And because word links identify the “sealed book” written “for the endtime” as the Book of Isaiah (Isaiah 29:11; 30:8), it too reveals “all things concerning my people which are of the house of Israel” (3 Nephi 23:2; emphasis added). Isaiah’s affirming that “the deaf shall hear the words of the book and the eyes of the blind see out of gross darkness” (Isaiah 29:18) thus suggests that the Gentiles’ learning the “truth,” “fulness,” and “all things” begins with the Book of Isaiah itself.
(Excerpt from Endtime Prophecy, pp. 424-425)