Jesus gave them strict orders not to tell anybody about this.
Then he warned his disciples not to tell anyone that he was the Messiah.
As they descended the mountain Jesus gave them strict instructions. “Don't tell anybody what you saw until the Son of man has risen from the dead,” he told them.
“Make sure you don't tell anyone,” Jesus told him. “Go and show yourself to the priest and give the offering which Moses required as public proof.”
And they could see. Then Jesus warned them, “Make sure nobody knows about this.”