Luke 9:36

And after the voice had spoken, Jesus was found alone. But the apostles kept quiet [about this incident], and did not tell anyone at that time about anything they had seen.

Matthew 17:9

And as they were coming down from the mountain, Jesus ordered them, saying, "Do not tell anyone about the vision [you have just seen] until the Son of man has been raised from the dead."

Mark 9:6

For he did not know what to say, because they [all] became very afraid.

Mark 9:9-10

And as they were coming down from the mountain Jesus ordered His disciples not to tell anyone what they had seen until [after] the Son of man was raised again from the dead.

Treasury of Scripture Knowledge

Summary

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.

General references

Bible References

And they

Matthew 17:9
And as they were coming down from the mountain, Jesus ordered them, saying, "Do not tell anyone about the vision [you have just seen] until the Son of man has been raised from the dead."
Mark 9:6
For he did not know what to say, because they [all] became very afraid.

General references

Mark 9:8
And suddenly they looked all around them, but the only one they saw with them was Jesus.