Regardless of the original source of this prophecy and regardless of whether it is a quotation or a paraphrase (Jacob has moved between the two in this very sermon), the emphasis is on hostility toward Zion, specifically from Jew and Gentile. He quotes this verse in the context of Isaiah’s prophecy that Zion’s salvation will ultimately come from the Gentiles, so why does he identify Zion’s two opponents?
In the New World context—especially the social reconstruction of the early Nephites—Jew and Gentile opponents are very significant. The Lamanites take the role of the Jews who oppose Zion, while the Lamanites’ political allies take the role of the Gentiles who oppose Zion. The Gentiles within the Nephite community are the “saviors” who fulfill the Isaiah prophecy.