What does Isaiah 19:18 mean?
Isaiah's prophecies in this chapter appear to point to two different seasons in Egypt's future. In the nearer season, Egypt will experience sweeping judgment from the Lord, leaving the nation divided and destitute (Isaiah 19:1–15). The second season is set further in the future, when the Lord will return to earth and establish His kingdom (Isaiah 2:1–5; Revelation 20:1–4). In that era, the Egyptians will know who the Lord is and respect His power to destroy them (Isaiah 19:16–17). Then something remarkable will happen: The people of Egypt will begin to turn to the Lord. They will worship the Lord as their own God.The passage states that five cities in Egypt will speak the language of Canaan. Scholars suggest that the meaning here is that those initial cities will be the beginning of a nationwide repentance. All of Egypt will end up swearing allegiance to the Lord in this time. The act of learning Israel's language may indicate a humility to fully adapt to the ways of God's people.
One of these five key cities will be called either the "City of Destruction" or the "City of the Sun," depending on the translation. The Hebrew words for "destruction" and "sun" are extremely similar, distinguished by a small dot under one letter. Many scholars believe "sun" is the more logical translation; a "City of Destruction" doesn't easily fit the context of repentance. Also, there is an Egyptian "City of the Sun" called Heliopolis, or "On." It was a center of worship to the Egyptian sun-god Ra. If the people of the City of the Sun abandoned Ra and swore allegiance to the Lord God of Israel, Egypt's repentance would surely be complete.