John Chrysostom
Catena Aurea · Markusevangelium 9
And he said unto them, Verily I say unto you, That there be some of them that stand here, which shall not taste of death, till they have seen the kingdom of God come with power. And after six days Jesus taketh with him Peter, and James, and John, and leadeth them up into an high mountain apart by themselves: and he was transfigured before them. And his raiment became shining, exceeding white as snow; so as no fuller on earth can white them. And there appeared unto them Elias with Moses: and they were talking with Jesus. And Peter answered and said to 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. For he wist not what to say; for they were sore afraid. And there was a cloud that overshadowed them; and a voice came out of the cloud, saying, This is my beloved Son: hear him. And suddenly, when they had looked round about, they saw no man any more, save Jesus only with themselves.
(Hom. in Matt. 56) The voice proceeded from a cloud in which God is wont to appear, that they might believe that the voice was sent forth from God. But in that He says, This is my beloved Son, He declares that the will of the Father and the Son is one, and that, save in that He is the Son, He is in all things One with Him who begot Him.