Augustine of Hippo
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.
(de Con. Ev. l. ii. c. 56.) Now in what Luke here says of Moses and Elias, And it came to pass as they departed from him, Peter said unto Jesus, Master, it is good for us to be here, he must not be thought contrary to Matthew and Mark, who have so connected Peter’s suggestion of this, as if Moses and Elias were still speaking with our Lord. For they did not expressly state that Peter said it then, but rather were silent about what Luke added, that as they departed, Peter suggested this to our Lord.