Charles Ellicott Commentary Matthew 17:9

"And as they were coming down from the mountain, Jesus commanded them, saying, Tell the vision to no man, until the Son of man be risen from the dead." — Matthew 17:9 (ASV)

Tell the vision to no man — The command obviously included the rest of the apostles within its prohibition. For them, in their lower stage of spiritual growth, a secondhand report of the vision would have led them either to distrust it or to pervert its meaning. For the time being, whatever reasons excluded them from being spectators applied with even greater force against them hearing about what had been seen from others.

It should be noted that the Greek word for “vision” means simply “what they had seen.” It does not suggest, as the English word does, the idea of a dream-state in those who saw it.