Matthew 1:21

Jesus... he shall save, &c. The characteristic name of Saviour was peculiar to the Messias, by which he was distinguished, as well as by the adorable name of Jesus. The expectations of both Jew and Gentile looked forward to a saviour. St. Augustine, in the 18th book, 23d chapter, de Civitate Die, introduces a curious anecdote. He mentions there, that he received from the eloquent and learned Proconsul Flactianus, a book containing in Greek the verses of one of the Sybils, which related to the coming of Christ. The substance of them is much the same as occurs in the prophecies of Isaiah, from which Virgil has likewise copied into his Pollio, many of the sublime thoughts which we find in that beautiful eclogue. It is remarkable that of the initials of these verses, St. Augustine had formed an acrostic to the following import, Greek: Iesous Christos Deos huios soter; that is, Jesus Christ, the Son of God, Saviour. (Haydock)