18 On that Day, more than one city in Egypt will learn to speak the language of faith and promise to follow God-of-the-Angel-Armies. One of these cities will be honored with the title "City of the Sun." 19 On that Day, there will be a place of worship to God in the center of Egypt and a monument to God at its border. 20 It will show how the God-of-the-Angel-Armies has helped the Egyptians. When they cry out in prayer to God because of oppressors, he'll send them help, a savior who will keep them safe and take care of them. 21 God will openly show himself to the Egyptians and they'll get to know him on that Day. They'll worship him seriously with sacrifices and burnt offerings. They'll make vows and keep them. 22 God will wound Egypt, first hit and then heal. Egypt will come back to God, and God will listen to their prayers and heal them, heal them from head to toe.
Matthew Henry's Commentary on Isaiah 19:18-22
Commentary on Isaiah 19:18-25
(Read Isaiah 19:18-25)
The words, "In that day," do not always refer to the passage just before. At a time which was to come, the Egyptians shall speak the holy language, the Scripture language; not only understand it, but use it. Converting grace, by changing the heart, changes the language; for out of the abundance of the heart the mouth speaks. So many Jews shall come to Egypt, that they shall soon fill five cities. Where the sun was worshipped, a place infamous for idolatry, even there shall be a wonderful reformation. Christ, the great Altar, who sanctifies every gift, shall be owned, and the gospel sacrifices of prayer and praise shall be offered up. Let the broken-hearted and afflicted, whom the Lord has wounded, and thus taught to return to, and call upon him, take courage; for He will heal their souls, and turn their sorrowing supplications into joyful praises. The Gentile nations shall not only unite with each other in the gospel fold under Christ, the great Shepherd, but they shall all be united with the Jews. They shall be owned together by him; they shall all share in one and the same blessing. Meeting at the same throne of grace, and serving with each other in the same business of religion, should end all disputes, and unite the hearts of believers to each other in holy love.