Matthew 17:8

So they looked up, and saw no one but Jesus.

Mark 9:8

Instantly they looked round, and now they could no longer see any one, but themselves and Jesus.

Luke 9:36

After this voice had spoken, Jesus was found alone. They kept it to themselves, and said not a word to any one at that time about what they had seen.

Acts 12:10-11

And passing through the first ward and the second, they came to the iron gate leading into the city. This opened to them of itself; and, going out, they passed on through one of the streets, and then suddenly the angel left him.

Treasury of Scripture Knowledge

Summary

And when they had lifted up their eyes, they saw no man, save Jesus only.

Bible References

They saw

Mark 9:8
Instantly they looked round, and now they could no longer see any one, but themselves and Jesus.
Luke 9:36
After this voice had spoken, Jesus was found alone. They kept it to themselves, and said not a word to any one at that time about what they had seen.
Acts 12:10
And passing through the first ward and the second, they came to the iron gate leading into the city. This opened to them of itself; and, going out, they passed on through one of the streets, and then suddenly the angel left him.