Isaías 9
Novatian · Comentário Patrístico (catena)
Isaías 9:6
Because he is of God, he is rightly called God, since he is the Son of God; and because he is subject to the Father and herald of the Father's will, he is proclaimed "Angel of Great Counsel." … The title [angel] does, however, suit the person of Christ, since he is not only God, inasmuch as he is the Son of God, but also a messenger, inasmuch as he is the herald of the Father's economy of salvation. Heretics must realize that they are acting contrary to the Scriptures when they say they believe that Christ was also an angel but do not want to admit that he is also the God who they read came frequently to visit the human race in the Old Testament. — ON THE TRINITY 18:9-10
Isaías 9:6
The title of angel is also appropriate to Christ because he was made "the Angel of Great Counsel." He is an angel because he lays bare the heart of the Father, as John declares. For if John says that this Word, who lays bare the bosom of the Father, was also made flesh, so that he could lay bare the heart of the Father, it follows that Christ is not only man but also an angel. And the Scriptures show not only that he is an angel but also that he is God. This is what we too believe. For, if we will not admit that it was Christ who then spoke to Hagar, we must either make an angel God or reckon God the Almighty Father among the angels. — ON THE TRINITY 18:22-23