And Jesus rebuked him - Chided him, or commanded him, with a threatening.
This was not the man that Jesus rebuked, but the spirit, for he instantly commanded the same being to come out of the man. In all this, Jesus did not once address the man. His conversation was with the evil spirit, proving conclusively that it was not a mere disease or mental derangement - for how could the Son of God hold converse with "disease" or "insanity?" - but that he conversed with a "being" who also conversed, reasoned, cavilled, felt, resisted, and knew him. There are, therefore, evil spirits, and those spirits have taken possession of human beings.
Hold thy peace - Greek, "Be muzzled." "Restrain thyself." "Cease from complaints, and come out of the man." This was a very signal proof of the power of Jesus, to be able by a word to silence an evil angel, and, against his will, to compel him to leave a man whom he delighted to torment.

And Jesus rebuked him - A spirit of this cast will only yield to the sovereign power of the Son of God. All watchings, fasting, and mortifications, considered in themselves, will do little or no good. Uncleanness, of every description, will only yield to the rebuke of God.

And Jesus rebuked him,.... Checking his insolence, despising his flattery, and refusing to receive a testimony from him; and which he wanted not, lest it should be thought he had a familiarity and confederacy with him:
saying, hold thy peace; stop thy mouth, I need no such witness as thine, nor thy praises; I am not to be soothed by thy flattery, nor is my mouth to be stopped, or power restrained, by such methods: wherefore he adds,
and come out of him: I will not let thee alone, thy encomiums of me shall not prevail upon me to leave thee in the quiet possession of the man; I will give a testimony of who I am, by the dispossessing of thee out of this man. In imitation of this authoritative power of Christ, the Jewish exorcists, in their pretensions to cast out devils, use a like form: so they tell us (q), that R. Simeon ben Jochai, cast a devil out of Caesar's daughter, saying, "Ben Talmion" (which was the name of the devil) "come out, Ben Talmion come out"; and he came out of her; See Gill on Matthew 12:27.
(q) T. Bab. Meilab, fol. 17. 2.

And Jesus rebuked him, saying, Hold thy peace, and come out of him--A glorious word of command. BENGEL remarks that it was only the testimony borne to Himself which our Lord meant to silence. That he should afterwards cry out for fear or rage (Mark 1:26) He would right willingly permit.