The phrase “the elements should melt with fervent heat” echoes the same phrase in 2 Peter 3:10. The phrase “earth should be wrapt together as a scroll” echoes Isaiah 34:4: “the heavens shall be rolled together as a scroll.” These are descriptions of the final days, and therefore fit the description that Jesus “did expound all things, even from the beginning until the time that he should come in his glory.”
That coming in glory will also signal the beginning of the final judgment, where the dead would “stand before God, to be judged of their works, whether they be good or whether they be evil.” As with Alma’s doctrine of restoration, good on earth is restored to good in Heaven, and evil to a “resurrection of damnation.”
This was the end of the chapter in the original Book of Mormon. Orson Pratt moved these verses to the beginning of the next chapter to be able to preserve the chapter and verses for the quoted Malachi chapters (see 3 Nephi, chapters 24-25 in our current edition).