Nephi references past fulfillments as a foundation for the future fulfillment of prophecy. While Isaiah may have specifically dealt with the Assyrian and Babylonian invasions of Old World Israel and Judah, Nephi’s use of Isaiah is to apply those prophecies of invasion and destructions to the future of the New World Israel, his own Nephites. Nephi addresses his future people by noting that “never hath any of them been destroyed save it were foretold them by the prophets of the Lord.” He will now continue with his revelation of their future. Nephi is placing himself alongside Isaiah. Isaiah is the textual support for what Nephi will tell them. Nephi is the prophetic mouth through which it comes.