The Savior’s explanatory discourse repeats the information about his future return as the Triumphant Messiah.
Reference: The theme of the last days has already received heavy emphasis. Jesus’s sermon recaps and reemphasizes those points. The concluding sentences combine several KJV allusions with which Joseph would have been familiar:
But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. (2 Pet. 3:10)
And all the host of heaven shall be dissolved, and the heavens shall be rolled together as a scroll: and all their host shall fall down, as the leaf falleth off from the vine, and as a falling fig from the fig tree. (Isa. 34:4)
The image of the heavens being rolled as a scroll (also Rev. 6:14) is inaccurate in this context. The Hebrews viewed heaven as a tent over the earth, keeping out the celestial waters. (See commentary accompanying 3 Nephi 24:10.) A tent can easily be rolled up, a metaphor for removing the barrier between heaven and earth.
In 3 Nephi, the scroll is applied to both heaven and earth, unlike the King James Version models in which only the heavens pass away. The only way the earth could also be rolled would be if it were a sheet of metal under intense heat that made it malleable enough to roll. Such an image fits Malachi 4:1, which foresees the refiner’s fire purifying the elements. Second, the Nephites did not have scrolls, but they did have sheets of metal. Thus, metaphorically speaking, the fire creates something pure from a corrupt original. The old earth and heavens being renewed through the refiner’s fire would have been a more readily understood metaphor in the New World. (See commentary accompanying Mormon 5:23.)