Isaiah 19:17

“And the land of Judah shall be a terror unto Egypt, &c.] Not by reason of war breaking out between them, they being in strict alliance with each other at this time; but on account of what they should hear had befallen the land of Judea, and the cities of it, by the invasion of Sennacherib’s army, which had taken and laid them waste; the tidings of which being brought them a panic would seize them, fearing that they should next fall a sacrifice to them, because of their alliance with them, and nearness to them, there being only the land of the Philistines between them and Egypt; and Judea being invaded and overrun, the way was open for the Assyrian army into their country; and besides they…”

“Judah . . . terror unto Egypt--not by itself: but at this time Hezekiah was the active subordinate ally of Assyria in its invasion of Egypt under Sargon. Similarly to the alliance of Judah with Assyria here is Kg2 23:29, where Josiah takes the field against Pharaoh-nechoh of Egypt, probably as ally of Assyria against Egypt [G. V. SMITH]. VITRINGA explains it that Egypt in its calamities would remember that prophets of Judah had foretold them, and so Judah would be "a terror unto Egypt." thereof--of Judah. it--Egypt.”

“And the land of Judah - The fear and consternation of Egypt shall be increased when they learn what events are occurring there, and what Yahweh has purposed in regard to it. Shall be a terror - This cannot be understood to mean that they were in danger from an invasion by the Jews, for at that time they were not at war, and Judah had no power to overrun Egypt. Jarchi and Kimchi suppose that the passage means that the Egyptians would hear what had occurred to the army of Sennacherib on its overthrow, and that they would be alarmed as if a similar fate was about to come upon them. But the more probable interpretation is that which refers it to the “invasion” of Judah by Sennacherib. The…”

“A terror - Because of their manifold injuries against Judah, for which they now apprehend God is calling them to account. Determined - Because God is now about to execute his appointed judgments. It - Against Egypt. Isaiah 19:18”

“the land: Isa 36:1; Jer 25:19, Jer 25:27-31, Jer 43:8-13, Jer 44:28-30; Eze 29:6, Eze 29:7 because: Isa 14:24, Isa 14:26, Isa 14:27, Isa 20:2-5, Isa 46:10, Isa 46:11; Dan 4:35 Isaiah 19:18”