Isaiah 19:17
And the land of Judah shall be a terror unto Egypt, every one that maketh mention thereof shall be afraid in himself, because of the counsel of the LORD of hosts, which he hath determined against it. And the land of Judah shall be a terror unto Egypt, every one that maketh mention thereof shall be afraid in himself, because of the counsel of the LORD of hosts, which he hath determined against it.
Isaiah 19:17 belongs to a prophecy concerning Egypt that declares God's judgment upon that nation. The land of Judah was to become a terror to Egypt, so that everyone who merely heard Judah mentioned would be afraid within himself because of the counsel of the Lord of hosts which He had determined against Egypt. This humbling of Egypt was foretold as punishment intended to teach the nation to know and fear the true God.
The surrounding prophecy describes the revolutions and future state of Egypt, foretelling that this ancient and powerful and defensible country would be invaded, conquered and spoiled, would fall into the hand of strangers, would become the basest of the kingdoms and rule over the nations no more, and would renounce idolatry. That fate was fulfilled across more than twenty-four centuries through Nebuchadnezzar, the Persians, the Macedonians under Alexander the Great, Rome, the Saracens, the Mamelukes, and the Turks. A great part of the chapter had already been fulfilled in Egypt.
The events of the chapter were probably all fulfilled centuries ago rather than in modern times. The prophecy points to the preaching of the gospel in Egypt and Assyria in New Testament times.