As the apostle once more recurs to the Father's voice, let us follow him also.
“And this voice we heard uttered (or, brought) out of heaven, being with him on the holy mountain” (ver. 18).
The three apostles were truly eye-witnesses of the Lord's majesty, all the more wondrous because it was His power and coming for a brief view in the midst of His humiliation in grace for God's glory. Every part of the scene before their eyes was a magnificent testimony to the future kingdom of the Son of man beheld on a small scale, before the Lord come to establish it in its visible grandeur and its appointed season before the universe. But the emphasis is manifestly laid on “this voice we heard,” borne out of heaven as it was, when we were with Him on the holy mountain.
Already had the Father's voice been heard in terms identical with these now recorded, save the pregnant construction of εἰς ὃν for ἐν ᾦ in the Gospel which makes no difference in translating. But none as far as we know, heard the first time but the Lord Himself and the Baptist, though the Lord adduced it as one of the four testimonies to His personal glory which proved the Jews to be thoroughly unbelieving: John the Baptist His predicted herald; then the greater witness which the Father gave Him to complete; next, the Father that sent Him had Himself borne witness concerning Him by His voice; and lastly the scriptures, to which He assigned a very great place (John 5). But man's will can resist any and all, as the Jews then verified to their ruin, and will another day and in another form, as He then warned them.
The occasion too was quite different. For the grace of the Lord Jesus led Him to take His place with the feeble remnant of the Jews who obeyed John's call to repentance, and came to the Jordan to be baptized as they did. Holy, guileless, undefiled, He associated Himself with those who had nothing but sins; yet as they confessed them, the first mark of awakened conscience bowing to God's call, He would not stand aloof though He had not the least evil to confess. It was the perfection of man's position in lowly active love; and so He, the Righteous One, corrected John's reluctance in the gracious words, Thus it becometh us (you and Me) to fulfill all righteousness. “And Jesus being baptized went up straightway from the water; and, behold, the heavens were opened to Him, and He saw the Spirit of God descending as a dove, and coming upon Him; and, behold, a voice out of the heavens, saying, This is my beloved Son, in whom I am well pleased.” The heavens opened to Him, the Holy Ghost's descent as a dove on Him, the Father's voice expressing His delight summed up there and then, bore witness to the divine delight in Him and never so much as in that act of humiliation in grace.
Yet at the mount of Transfiguration the immediate occasion of the voice again heard, and by the chosen witnesses, was Peter's own attempt to honor His master in the highest way he could then suggest. But to put Him on a level with the chiefs of the law and the prophets would not suit the Father. “This is my beloved Son: hear Him.” And the terrified disciples fell upon their faces; but lifted up at the touch and the comforting words of their Master, they saw no one but Jesus, alone with themselves. He was to be heard, He paramountly, He the truth. Others at best wore His forerunners.
As noticed already, Peter here was not led to recall this last part of the utterance given in all the synoptic Gospels. His aim was to concentrate attention on Jesus as the center of divine affection and glory; theirs was also to attest Him as the complete fullness and revealer of all the truth. Matthew gives the Father's voice undiminished: as his province was to show the full consequence of the rejected Messiah, His larger glory as Son of man, and higher still as the beloved Son of God, the Rock on which the church was to be built. Mark and Luke omit here the expression of God's complacency in Him, so as to throw stress on hearing Him, the former as the Servant Son in the gospel; the latter as God's Son, yet fully man. Our apostle omits the clause they carefully record, not because he could or would forget it, but to make the more prominent the good pleasure the Father had in Him, His beloved Son.