וְחָלַ֤ף בִּֽיהוּדָה֙ שָׁטַ֣ף וְעָבַ֔ר עַד־צַוָּ֖אר יַגִּ֑יעַ וְהָיָה֙ מֻטּ֣וֹת כְּנָפָ֔יו מְלֹ֥א רֹֽחַב־אַרְצְךָ֖ עִמָּ֥נוּ אֵֽל׃ (ס)
And he shall sweep through Judah Overflowing as he passeth through He shall reach even to the neck; And the stretching out of his wings Shall fill the breadth of thy land, O Immanuel.
Ibn Ezra on Isaiah
Immanuel. He is mentioned here because he is to serve as a sign that Jerusalem will be delivered out of the hand of Pekah, Rezin and Sennacherib, even after the conquest of Damascus and Samaria.16The Assyrian armies could then march directly against Jerusalem, and their success was considered certain.