Isaiah 19:22
And the LORD shall smite Egypt: he shall smite and heal it: and they shall return even to the LORD, and he shall be intreated of them, and shall heal them. And the LORD shall smite Egypt: he shall smite and heal it: and they shall return even to the LORD, and he shall be intreated of them, and shall heal them.
Isaiah 19:22 belongs to a prophecy concerning Egypt, of which a great part has already been fulfilled there. That fulfillment took place centuries ago rather than in modern times. It foretells the spread of God's truth and its fruits in Egypt, pointing to the preaching of the gospel in Egypt and Assyria in New Testament times.
Its fulfillment included strong Christian churches and centers in Egypt, with the altar representing a center of worship where people gathered. The smiting and healing mean that God would humble Egypt through national distress and then restore it. That suffering would turn its people back to the Lord, who would hear them and heal them. God's purpose in breaking Egypt's idols and ambitions was to lead its people to seek Him and receive lasting good.