Wherefore Matthew relates that the voice said, “This is my beloved Son;” for he wished to shew that the words, “This is My Son,” were in fact said, that thus the persons who heard it might know that He, and not another, was the Son of God.
But if you ask which of these two sounded forth in that voice, take which you will, only remember, that the Evangelists, though not relating the same form of speaking, relate the same meaning. And that God delighted Himself in His Son, we are reminded in these words, “In thee I am well pleased.”
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: de Con. Ev., ii, 14