What does Isaiah 19:25 mean?

In Isaiah's distant future, he sees a prophetic vision that Egypt will repent before the Lord God of Israel. The people will join in proper worship (Isaiah 19:19–22). The prophecy follows Isaiah's oracle about Egypt's coming destruction (Isaiah 19:1–15). Even more remarkable than Egypt's repentance is the change in Assyria: a culture renowned for conquest and savage cruelty. In that future day, even the Assyrians will turn and worship Israel's God (Isaiah 19:23).Those two great nations will join Israel to make a three-nation grouping that will be a blessing in the earth (Isaiah 19:24).

How could such an unimaginable thing be possible? Only one way: The Lord of hosts will make it so. He will call those nations to repent and worship Him alone. Then He will bless them in powerful ways that sound remarkably like His powerful promises to Israel.

The Lord will refer to Egypt and Assyria—or the nations corresponding to those cultures in the future—as His people. Not only that, but He will also call both nations blessed. God will finally and fully keep His promise to bless all the families of the earth through His people Israel (Genesis 12:1–3). There is never a promise that God will not keep, He will fulfill it in His perfect timing.

This will be possible only through the Messiah. The people of Egypt and Assyria will come to God through faith in Jesus Christ. The Messiah will rule from His throne in Jerusalem over all the nations (Isaiah 2:1–5; Revelation 20:1–4).

Many years later, Paul would describe the people of these other nations as the sons of Abraham by faith in Christ : "Know then that it is those of faith who are the sons of Abraham…those who are of faith are blessed along with Abraham, the man of faith" (Galatians 3:7–9).