John 13:37

why not . . . now? I will lay down my life for thy sake--He seems now to see that it was death Christ referred to as what would sever Him from them, but is not staggered at following Him thither. Jesus answered,

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).

13:37 Peter claimed to be ready to die for Jesus, yet his denials are well known (18:15-18, 25-27; see also Matt 26:32-34; Mark 14:27-30; Luke 22:31-34). Although Peter’s verve and devotion failed, he was restored (John 21:15-19).