Except for the quotations from Isaiah, Nephi’s vision, beginning with the tree of life and ending with his apocalyptic vision is the longest narration on a single theme in the Book of Mormon. Yet he wrote “but a small part of the things which I saw.”
Nephi made this record long after the vision itself and inserted it into a historical account of the Lehite exodus from Jerusalem. Even though Lehi’s tree of life vision triggered Nephi’s own vision, as he sought understanding, that vision moved quite rapidly beyond Lehi’s dream, expanding outward until it included John’s apocalypse.