There came a cloud,— A bright cloud, St. Matthew calls it, Matthew 17:5 and St. Peter, the excellent glory, 2 Peter 1:17 whence we conclude, that it must have been the Shechinah, or visible symbol of the divine presence; as is evident also from the words that came out of the cloud, which were the words of God himself; This is my Son, the Beloved, hear him. The voice uttering these words just as Moses and Elias disappeared, intimated that men were no longer to hearken unto them, speaking in the law, but for the future were to obey Jesus; because Moses and Elias, though both eminent in their stations, were only servants; whereas this was God's beloved Son. Besides, the sentence uttered by the voice, hear ye him, plainly alluding to Deuteronomy 18:15 signified that Jesus wasthe prophet of whom Moses spake in that passage. See the note there.
Related Commentaries of Luke 9:34
Luke 9:34-35
34 While he thus spake, there came a cloud, and overshadowed them: and they feared as they entered into the cloud.
35 And there came a voice out of the cloud, saying, This is my beloved Son: hear him.