Hilary of Poitiers
Catena Aurea · Matthäusevangelium 17
While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him. And when the disciples heard it, they fell on their face, and were sore afraid. And Jesus came and touched them, and said, Arise, and be not afraid. And when they had lifted up their eyes, they saw no man, save Jesus only. And as they came down from the mountain, Jesus charged them, saying, Tell the vision to no man, until the Son of man be risen again from the dead.
This is the Son, this the Beloved, this the Accepted; and He it is who is to be heard, as the voice out of the cloud signifies, saying, Hear ye Him. For He is a fit teacher of doing the things He has done, who has given the weight of His own example to the loss of the world, the joy of the cross, the death of the body, and after that the glory of the heavenly kingdom.