John Trapp on Isaiah 19:18

Ver. 18. In that day] When the Goſpel ſhall be there preached, whether by Mark the Evangeliſt or others, as Clement, Origen, Didymus.

Five Cities] A conſiderable number of Aegyptians.

Speak the Language of Canaan] Called the Jews language, chap. 35.11, 13. the Hebrew tongue wherein were written the lively Oracles of God. This Language therefore the Elect Egyptians ſhall learn, and labour for that pure lip, Zeph. 3.9. to ſpeak as the Oracles of God, 1 Pet 4.11. Wholſom words, 2 Tim. 1.13. Right words. Job 6.25. Words of wiſdom, Prov. 1.6. Of truth and ſoberneſs, Act. 26.25. to be Examples to others, not only in faith and converſation, but alſo in words and communication, 1 Tim. 4.12.

And ſwear to the Lord of hoſts] Devote themſelves to his fear and ſervice,Nempe ſuſceptione baptiſmi. Piſcat. taking a corporal oath for that purpoſe as in baptiſme, and other holy covenants: whereupon haply they might be inabled to ſpeak with tongues, the holy tongue eſpecially, as moſt neceſſary for Chriſtians. Here then we have a deſcription of a true Chriſtian, not ſuch as the Jeſuites in their Catechiſme give us, viz. A Chriſtian is he who believeth whatſoever the Church of Rome commandeth to be believed, ſwearing fealty to Her.

One ſhall be called the City of deſtruction] i. e. Nevertheleſs there ſhall be a few cities that ſhall deſpiſe Chriſtian Religion; and ſhall therefore be deſtroyed for neglecting ſo great ſalvation: It ſhall be eaſier for Sodom one day then for ſuch. Others render the text, Heliopolis or the city of the Sun ſhall be accounted one, ſc. of thoſe 5 converted cities; and become conſecrated to the Sun of righteouſneſs. Joſeph. Ant. l[illegible: 1 letter]b. 13. cap. 6.