John 13:8

Peter saith unto him, Thou shalt never wash, &c.--more emphatically, "Never shalt Thou wash my feet": that is, "That is an incongruity to which I can never submit." How like the man! If I wash thee not, thou hast no part with me--What Peter could not submit to was, that the Master should serve His servant. But the whole saving work of Christ was one continued series of such services, ending with and consummated by the most self-sacrificing and transcendent of all services: THE SON OF MAN CAME not to be ministered unto, but TO MINISTER, AND TO GIVE HIS LIFE A RANSOM FOR MANY. (See on Mar 10:45). If Peter then could not submit to let his Master go down so low as to wash his feet, how should he suffer himself to be served by Him at all? This is couched under the one pregnant word "wash," which though applicable to the lower operation which Peter resisted, is the familiar scriptural symbol of that higher cleansing, which Peter little thought he was at the same time virtually putting from him. It is not humility to refuse what the Lord deigns to do for us, or to deny what He has done, but it is self-willed presumption--not rare, however, in those inner circles of lofty religious profession and traditional spirituality, which are found wherever Christian truth has enjoyed long and undisturbed possession. The truest humility is to receive reverentially, and thankfully to own, the gifts of grace.

Our Saviour having finished his public discourses, in which he "endured the contradiction of sinners," now applies himself to a private conversation with his friends, in which he designed the consolation of saints. Henceforward we have an account of what passed between him and his disciples, who were to be entrusted with the affairs of his household, when he was gone into a far country; the necessary instructions and comforts he furnished them with. His hour being at hand, he applies himself to set his house in order. In this chapter I. He washes his disciples' feet (v. 1-17). II. He foretels who should betray him (Joh 13:18-30). III. He instructs them in the great doctrine of his own death, and the great duty of brotherly love (Joh 13:31-35). IV. He foretels Peter's denying him (Joh 13:36-38).

13:8 Based on the depth of his devotion to Jesus, it is understandable that Peter protested. But Jesus was not simply giving Peter a model of service; this was a symbolic pre-enactment of his greater act of sacrifice on the cross (13:7). Receiving Jesus’ spiritual cleansing is a condition for discipleship, so if Peter could not accept this act, he could not be Jesus’ disciple at all.