When the millennium arrives, there will be a time for improving the vineyard. At the end of that time will come the final end. At the end of the time allotted for this earth, there will be a final division between the wicked and the righteous. After the righteous are gathered to the Lord of the vineyard, the bad are “cast away into [their] own place.” The end of the earth is characterized by burning. As with other images of burning from this agrarian society, it is perhaps a signal of reseeding and renewal. We see nothing that comes after that burning, but we need not see it as a destruction. Perhaps it is a different beginning, when “the earth will be renewed and receive its paradisiacal glory” (Tenth Article of Faith).
Jacob ends a chapter with the end of the long quotation from Zenos. It is probable that it was the ending of the quotation that triggered the end of the chapter, as the next chapter is clearly the continuation of the discourse begun in Chapter 4.