Nephi begins to focus on the parts of Isaiah’s prophecies that had not yet been fulfilled. Perhaps unsurprisingly, they will focus on the Messiah.
At this point, Nephi knows that there was been a scattering. With the revealed reality of the destruction of Jerusalem, what he knows is that there is a scattered Jerusalem. Thus, one of the first prophecies awaiting fulfillment is the return of Israel to Jerusalem. Therefore, in verse 10 he notes the destruction of Jerusalem and the carrying away of many of the Jews to Babylon.
That constitutes a revealed reality. Now, in verse 11, Nephi speaks “because of the spirit which is in me.” That spirit tells him that there will be a return to Jerusalem. This comes as a partial fulfillment of Isaiah’s prophecies that a remnant would return.