What does Isaiah 20:5 mean?
Many smaller nations around Egypt hoped that aligning themselves with the Egyptians would save them from Assyria. Isaiah has demonstrated with his humiliating appearance what the Egyptians will look like when they are eventually marched away into Assyrian captivity: exposed and helpless (Isaiah 20:2–3). It is not the picture of a victorious people or a people in a position to save others.Isaiah now says that those nations will be distraught because they put their hope in Cush. These nations will even be embarrassed that they boasted about Egypt saving them from the Assyrians. Cush was a smaller nation south of Egypt, but its dynasty was ruling over Egypt at this time.
Some in Judah had been attracted to the idea of aligning themselves with Egypt in hopes of being freed from Assyrians oppression. The Lord is insistent: Egypt cannot protect you. Only the Lord their God can save them from this threat, or any future threat.