Nephi's invocation "O house of Israel" makes it appear that he is citing a scripture here, as his direct audience is his brothers. However, the essential phrasing of this verse is not found elsewhere in the Old Testament. Remembering that Nephi is writing an account of this discussion, not transcribing a verbatim account may account for his switch in "virtual audiences". While he is discussing his exegesis to his brothers, he nevertheless is caught up again in what he has seen, and address Israel directly. Israel has been a theme in Nephi's writings, and his concern for the people that he has left is clear, and possibly most apparent in this "slip of the pen".
The essence of the prediction is that those who fight against Israel will get the worst of it, and the promises to Israel will prevail against that body labeled "that great and abominable church". That church of the devil will be defeated in the end, for however long it held sway in the interim.