Verse 21. - And he straitly charged them, and commanded them to tell no man that thing. It would have been no hard task for the disciples to have gone about with an expression of their earnest conviction that the great Prophet was indeed the long looked-for King Messiah, and thus to have raised the excitable crowds to any wild pitch of enthusiasm. It was only a very short time back that, moved by the miracle of the loaves, the multitudes wished to crown him King by force. That was not the kind of homage Jesus sought; besides which, any such enthusiasm thus evoked would quickly have died away, and a hostile reaction would have set in when the high hopes excited by the idea of King Messiah were contradicted by the life of suffering and self-denial which Jesus sternly set himself to live through to its bitter end. This life he sketched out for them in the severe language of the next verse.

9:18-27 It is an unspeakable comfort that our Lord Jesus is God's Anointed; this signifies that he was both appointed to be the Messiah, and qualified for it. Jesus discourses concerning his own sufferings and death. And so far must his disciples be from thinking how to prevent his sufferings, that they must prepare for their own. We often meet with crosses in the way of duty; and though we must not pull them upon our own heads, yet, when they are laid for us, we must take them up, and carry them after Christ. It is well or ill with us, according as it is well or ill with our souls. The body cannot be happy, if the soul be miserable in the other world; but the soul may be happy, though the body is greatly afflicted and oppressed in this world. We must never be ashamed of Christ and his gospel.And he strictly charged them, and commanded them,.... Though he highly approved of this their confession, and pronounced Peter blessed upon it; and signified that it was a discovery which flesh and blood could not make, but what was made to him his Father: yet he gave them a strict charge, and laid his commands on them,

to tell no man that thing; that he was the Messiah, and the eternal Son of God, and the true God, as well as the son of man, and really man: the reasons for this: See Gill on Matthew 16:20.