Matthew 16:22

And observe that it is not said,' He began to say,' or 'to teach,' but to show; for as things are said to be shown to the sense, so the things which Christ spake are said to be shown by Him. Nor indeed do I think, that to those who saw Him suffering many things in the flesh, were those things which they saw so shown as this representation in words showed to the disciples the mystery of the passion and resurrection of Christ. At that time, indeed, He only began to show them, and afterwards when they were more able to receive it, He showed them more fully; for all that Jesus began to do, that He accomplished. He must needs go to Jerusalem, to be put to death indeed in the Jerusalem which is below, but to rise again and reign in the heavenly Jerusalem. But when Christ rose again, and others were risen with Him, they no longer sought the Jerusalem which is beneath, or the house of prayer in it, but that which is above. He suffers many things from the elders of the earthly Jerusalem, that He may be glorified by those heavenly elders who receive His mercies. He rose again from the dead on the third day, that He may deliver from the evil one, and purchase for such as are so delivered this gift, that they be baptized in spirit, soul, and body, in the name of the Father, and the Son, and the Holy Spirit, who are three days perpetually present to those that through them have been made children of light. While Christ was yet speaking the beginnings of the things which He was showing unto them, Peter considered them unworthy of the Son of the living God. And forgetting that the Son of the living God does nothing, and acts in no way worthy of blame, he began to rebuke Him; and this is what is said, And Peter took him, and began to rebuke him. As though Christ Himself had needed a propitiation. […]

The Lord, knowing the suggestion of the craft of the devil, says to Peter, Get thee behind me; that is, that he should follow the example of His passion; but to him by whom this expression was suggested, He turns and says, Satan, thou art an offence unto me. For we cannot suppose that the name of Satan, and the sin of being an offence, would be imputed to Peter after those so great declarations of blessedness and power that had been granted him.

We have often said that Peter had too hot a zeal, and a very great affection towards the Lord the Saviour. Therefore after that his confession, and the reward of which he had heard from the Saviour, he would not have that his confession destroyed, and thought it impossible that the Son of God could be put to death, but takes Him to him affectionately, or takes Him aside that he may not seem to be rebuking his Master in the presence of his fellow disciples, and begins to chide Him with the feeling of one that loved Him, and to contradict Him, and say, Be it far from thee, Lord; or as it is better in the Greek, ἵλεώς σοι Κύριε, οὐ μὴ ἔσται σοι τοῦτο, that is, Be propitious to Thyself, Lord, this shall not be unto Thee. But to me this error of the Apostle, proceeding from the warmth of his affection, will never seem a suggestion of the devil. Let the thoughtful reader consider that that blessedness of power was promised to Peter in time to come, not given him at the time present; had it been conveyed to him immediately, the error of a false confession would never have found place in him. As much as to say; It is of My will, and of the Father's will, that I should die for the salvation of men; you considering only your own will would not that the grain of wheat should fall into the ground, that it may bring forth much fruit; therefore as you speak what is opposed to My will, you ought to be called My adversary. For Satan is interpreted 'adverse' or 'contrary.'

Therefore, the rest being troubled and in perplexity, Peter again, in his ardor, alone ventures to discourse of these things; and not even he openly, but when he had taken Him apart; that is, having separated himself from the rest of the disciples; and he saith, "Be it far from Thee, Lord, this shall not be unto Thee." What ever is this? He that obtained a revelation, he that was blessed, hath he so soon fallen away, and suffered overthrow, so as to fear His passion? And what marvel, that one who had not on these points received any revelation, should have that feeling? Yea, to inform thee that not of himself did he speak those other things either, see in these matters that were not revealed to him how he is confounded and overthrown, and being told ten thousand times, knows not what the saying can mean. For that He is Son of God he had learnt, but what the mystery of the cross and of the resurrection might be, was not yet manifest to him: for "the saying," it is said, "was hid from them." Seest thou that with just cause He bade them not declare it to the rest? For if it so confounded them, who must needs be made aware of it, what would not all others have felt?

For what wonder is it that this should befal Peter, who had never received a revelation concerning these things? For that you may learn that that confession which he made concerning Christ was not spoken of himself, observe how in these things which had not been revealed to him, he is at a loss. Estimating the things of Christ by human and earthly principles, he judged it mean and unworthy of Him that He should suffer. Therefore the Lord added, For thou savourest not the things that be of God, but the things that be of men.