Bede the Venerable
Catena Aurea · Lukasevangelium 9
But Peter and they that were with him were heavy with sleep: and when they were awake, they saw his glory, and the two men that stood with him. And it came to pass, as they departed from him, Peter said unto Jesus, Master, it is good for us to be here: and let us make three tabernacles; one for thee, and one for Moses, and one for Elias: not knowing what he said. While he thus spake, there came a cloud, and overshadowed them: and they feared as they entered into the cloud. And there came a voice out of the cloud, saying, This is my beloved Son: hear him. And when the voice was past, Jesus was found alone. And they kept it close, and told no man in those days any of those things which they had seen.
And mark, that as when our Lord was baptized in Jordan, so also when He was glorified on the Mount, the mystery of the whole Trinity is declared; for His glory which we confess at baptism, we shall see at the resurrection. Nor in vain does the Holy Spirit appear here in the cloud, there in the form of a dove, seeing that he who now preserves with a simple heart the faith which he receives, shall then in the light of open vision look upon those things which he believed.