Isaiah 19:17 is more specific than Isaiah 19:16. Even the mention of the Lord would cause terror. God's power was evident in the deliverance of his people, and there would now be no more doubt in the Egyptians' minds about where their judgment was coming from. This can be seen as a partial fulfillment of the promise in Deuteronomy 2:25: This day I will begin to put the dread and fear of you on the peoples who are under the whole heaven, who shall hear the report of you and shall tremble and be in anguish because of you.
17 And the land of Judah will become a terror to the Egyptians. Everyone to whom it is mentioned will fear because of the purpose that the LORD of hosts has purposed against them.