But some say, that it was after His incarnation, that Christ was called a Son in right of His baptism like the other saints, whom the Lord refutes by this place, saying, “I will send my Son.” Therefore when He thus meditated sending His Son after the Prophets, He must have been already His Son. Further, if He had been His Son in the same way as all the saints to whom the word of God was sent, He ought to have called the Prophets also His sons, as He calls Christ, or to call Christ His servant, as He calls the Prophets.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).