After the voice had spoken, only Jesus was present with them. The disciples kept this to themselves, and in those days they did not tell anyone what they had seen.
KJV
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.
ASV
And when the voice came, Jesus was found alone. And they held their peace, and told no man in those days any of the things which they had seen.