Charles Spurgeon Commentary Matthew 17:6

"And when the disciples heard it, they fell on their face, and were sore afraid." — Matthew 17:6 (ASV)

Yes, the voice overcame them. Deeper impression was produced by the words of the Lord than by the blinding light. “When the disciples hear it, they fell on their face, and were sore afraid.” They were in the immediate presence of God and listening to the Father’s voice. They might well lie prostrate and tremble. Too clear a manifestation of God, even though it related to Jesus, would rather overpower than empower us.

The three disciples said no more about building tabernacles, but as one man, “They fell on their face.” Awe is the end of talk. In this case, it looked as if it were the end of consciousness, but this was only a temporary faint, from which they would recover and be all the more joyous.