And as they came down from the mountain, he charged them that they should tell no man what things they had seen, till the Son of man was risen from the dead.
All Commentaries on Mark 9:9 Go To Mark 9
John Chrysostom
AD 407
So He bound them to silence. Furthermore he spoke of his passion as though it were the reason why he asked them to be silent. Note that he did not tell them that they must never tell this to anyone. Instead they should not tell it until he had risen from the dead. In this respect he was silent as to what was painful, and spoke only of what was joyful. Gospel of St. Matthew, Homily
