Just as verses speaking of Zion and Tabernacles evoke in our minds the latter day gathering place in the Salt Lake Valley, and the spreading of latter-day temples, I believe Isaiah’s messianic words would have taken on a unique application for Nephi and his people.
After all, had they not been led through the desert as if with “a cloud and smoke by day and the shining of a flaming fire by night?” Had they not just reenacted the exodus by being led to a promised land? Had they not built a new temple to the Lord in their chosen land?
This, again, I see Nephi quoting Isaiah for a dual purpose. First, to provide comfort, guidance, and assurances to his people. They had built a Zion society, if they could keep and maintain it. Second, to reveal to his people (and to us) the promises of the Lord unto Israel in the Latter-days.
I have repeated these themes over several posts because I believe that once we see this extra gloss on Isaiah, it helps us more fully understand why these words were so precious to Nephi.