And he shall pass through Judah; rather, he shall pass on into Judah ("He shall sweep onward into Judah," Revised Version). The Assyrians will not be content with invading Syria and Samaria; they will "pass on into Judaea."
It is not clear whether this is to be done immediately by Tiglath-Pileser, or by one of his successors at a later date. There is reason to believe from Tiglath-Pileser's inscriptions that he used the territory of Ahaz for the passage of his armies as those of a vassal king, but did not ravage them.
He shall reach even to the neck. The Assyrian attacks on Judaea shall stop short of destroying it. The flood shall not submerge the head, but only rise as high as the neck. This prophecy was fulfilled, since it was not Assyria, but Babylon, which destroyed the Jewish kingdom.
The stretching out of his wings shall fill the breadth of thy land. The Assyrian armies shall visit every part of the land. The sudden change of metaphor is in the manner of Isaiah (see Isaiah 1:30, Isaiah 1:31; Isaiah 5:24, Isaiah 5:30, etc.
). O Immanuel. On the importance of this address, as indicating the kingly, and so (probably) the Divine character of Immanuel, see the notes on Isaiah 7:14. Isaiah could not speak of the land as belonging to his own infant son.