17 And after six days Jesus taketh Peter, James, and John his brother, and bringeth them up into an high mountain apart, 2 And was transfigured before them: and his face did shine as the sun, and his raiment was white as the light. 3 And, behold, there appeared unto them Moses and Elias talking with him. 4 Then answered Peter, and said unto Jesus, Lord, it is good for us to be here: if thou wilt, let us make here three tabernacles; one for thee, and one for Moses, and one for Elias. 5 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. 6 And when the disciples heard it, they fell on their face, and were sore afraid. 7 And Jesus came and touched them, and said, Arise, and be not afraid. 8 And when they had lifted up their eyes, they saw no man, save Jesus only.9 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. 10 And his disciples asked him, saying, Why then say the scribes that Elias must first come? 11 And Jesus answered and said unto them, Elias truly shall first come, and restore all things. 12 But I say unto you, That Elias is come already, and they knew him not, but have done unto him whatsoever they listed. Likewise shall also the Son of man suffer of them. 13 Then the disciples understood that he spake unto them of John the Baptist. Matthew 17 (KJV 1900)
Ancient Faith Radio have put together a handful of past episodes on the upcoming feast of the Transfiguration including some homilies and some great discussion on the feast in there series section here. Recommended.
Why was it that when they heard these words they were dismayed? For previously a similar voice had spoken in Jordan and a crowd was present, but no one felt anything like this; and afterwards, again, when they said that it thundered, they did not feel anything like this. Why then did they fall on their faces on the mountain? Because there was solitude, and the height of the mountain, and great quietness, and a transfiguration full of awe, and a pure light and a cloud stretched out; all of these threw them into great alarm. Amazement arose on every side, and they fell on their faces in both fear and adoration at the same time. St John Chrysostom – The Gospel of Matthew, Homily 56.6