matthew 16:23 But he turned, and said unto Peter, Get thee behind me, Satan: thou art an offence unto me: for thou savourest not the things that be of God, but those that be of men. - Free Bible Online

      23. But he turned, and said--in the hearing of the rest; for Mark (Mr 8:33) expressly says, "When He had turned about and looked on His disciples, He rebuked Peter"; perceiving that he had but boldly uttered what others felt, and that the check was needed by them also.
      Get thee behind me, Satan--the same words as He had addressed to the Tempter (Lu 4:8); for He felt in it a satanic lure, a whisper from hell, to move Him from His purpose to suffer. So He shook off the Serpent, then coiling around Him, and "felt no harm" (Ac 28:5). How quickly has the "rock" turned to a devil! The fruit of divine teaching the Lord delighted to honor in Peter; but the mouthpiece of hell, which he had in a moment of forgetfulness become, the Lord shook off with horror.
      thou art an offence--a stumbling-block.
      unto me--"Thou playest the Tempter, casting a stumbling-block in My way to the Cross. Could it succeed, where wert thou? and how should the Serpent's head be bruised?"
      for thou savourest not--thou thinkest not.
      the things that be of God, but those that be of men--"Thou art carried away by human views of the way of setting up Messiah's kingdom, quite contrary to those of God." This was kindly said, not to take off the sharp edge of the rebuke, but to explain and justify it, as it was evident Peter knew not what was in the bosom of his rash speech.

JFB.