John 13:38

The love which St. Peter bore our Saviour was exceedingly tender, but it was not yet sufficiently strong. (St. Bernard, Serm. iv. in Cant.) — Jesus therefore asks him, Wilt thou lay down thy life for me? Do you think yourselves sufficiently strong to perform this heroic act for love of me? so far are you from exposing your life for me, that you will shortly deny me. (Menochius)

2. Christ gives him a surprising prediction of his inconstancy, v. 38. Jesus Christ knows us better than we know ourselves, and has many ways of discovering those to themselves whom he loves, and will hide pride from. (1.) He upbraids Peter with his confidence: Wilt thou lay down thy life for my sake? Me thinks, he seems to have said this with a smile: "Peter, thy promises are too large, too lavish to be relied on; thou dost not consider with what reluctancy and struggle a life is laid down, and what a hard task it is to die; not so soon done as said." Christ hereby puts Peter upon second thoughts, not that he might retract his resolution, or recede from it, but that he might insert into it that necessary proviso, "Lord, thy grace enabling me, I will lay down my life for thy sake." "Wilt thou undertake to die for me? What! thou that trembledst to walk upon the water to me? What! thou that, when sufferings were spoken of, criedst out, Be it far from thee, Lord? It was an easy thing to leave thy boats and nets to follow me, but not so easy to lay down thy life." His Master himself struggled when it came to his, and the disciple is not greater than his Lord. Note, It is good for us to shame ourselves out of our presumptuous confidence in ourselves. Shall a bruised reed set up for a pillar, or a sickly child undertake to be a champion? What a fool am I to talk so big. (2.) He plainly foretels his cowardice in the critical hour. To stop the mouth of his boasting, lest Peter should say it again, Yea Master, that I will, Christ solemnly asserts it with, Verily, verily, I say unto thee, the cock shall not crow till thou hast denied me thrice. He does not say as afterwards, This night, for it seems to have been two nights before the passover; but, "Shortly thou wilt have denied me thrice within the space of one night; nay, within so short a space as between the first and last crowing of the cock: The cock shall not crow, shall not have crowed his crowing out, till thou has again and again denied me, and that for fear of suffering." The crowing of the cock is mentioned, [1.] To intimate that the trial in which he would miscarry thus should be in the night, which was an improbable circumstance, but Christ's foretelling it was an instance of his infallible foresight. [2.] Because the crowing of the cock was to be the occasion of his repentance, which of itself would not have been if Christ had not put this into the prediction. Christ not only foresaw that Judas would betray him though he only in heart designed it, but he foresaw that Peter would deny him though he did not design it, but the contrary. He knows not only the wickedness of sinners, but the weakness of saints. Christ told Peter, First, That he would deny him, would renounce and abjure him: "Thou wilt not only not follow me still, but wilt be ashamed to own that ever thou didst follow me." Secondly, That he would do this not once only by a hasty slip of the tongue, but after he had paused would repeat it a second and third time; and it proved too true. We commonly give it as a reason why the prophecies of scripture are expressed darkly and figuratively, because, if they did plainly describe the event, the accomplishment would thereby either be defeated or necessitated by a fatality inconsistent with human liberty; and yet this plain and express prophecy of Peter's denying Christ did neither, nor did in the least make Christ accessary to Peter's sin. But we may well imagine what a mortification it was to Peter's confidence of his own courage to be told this, and to be told it in such a manner that he durst not contradict it, else he would have said as Hazael, What! is thy servant a dog? This could not but fill him with confusion. Note, The most secure are commonly the least safe; and those most shamefully betray their own weakness that most confidently presume upon their own strength, 1 Cor 10 12.

Verses 36-38 What Christ had said concerning brotherly love, Peter overlooked, but spoke of that about which Christ kept them ignorant. It is common to be more eager to know about secret things, which belong to God only, than about things revealed, which belong to us and our children; to be more desirous to have our curiosity gratified, than our consciences directed; to know what is done in heaven, than what we may do to get thither. How soon discourse as to what is plain and edifying is dropped, while a doubtful dispute runs on into endless strife of words! We are apt to take it amiss to be told we cannot do this and the other, whereas, without Christ we can do nothing. Christ knows us better than we know ourselves, and has many ways of discovering those to themselves, whom he loves, and he will hide pride from them. May we endeavour to keep the unity of the Spirit in the bond of peace, to love one another with a pure heart fervently, and to walk humbly with our God.