Peter had just heard a hard word about his own future: "another shall gird thee, and carry thee whither thou wouldest not" (John 21:18). Now he wanted to know what lay ahead for his companion. Commentators read his motive differently. Barnes suggests that Peter perhaps suspected John "would have a happier lot," though he allows it may have been from "kindness to John." Gill says Peter asked "partly out of curiosity, and partly out of concern for him," since the two were close friends. Matthew Henry notes that Peter "seems more concerned for another than for himself."

Jesus answered, "If I will that he tarry till I come, what is that to thee? follow thou me" (John 21:22). He did not tell Peter John's future; He turned Peter back to his own calling. A saying then spread among the brethren that this disciple would not die, but John corrects it: "yet Jesus said not unto him, He shall not die" (John 21:23).

Jesus had just foretold Peter's death. John explains that He said it "signifying by what death he should glorify God" (John 21:19). Barnes reports the ancient tradition that Peter was later crucified at Rome. Scripture itself does not record Peter's death.

The rumor in John 21:23 shows how easily a saying of Jesus could be misunderstood. Gill sees John's careful correction as a sign of "his integrity and love of truth."

Jesus calls each disciple to follow Him on a path that is his own. Peter's road would end in a death that glorified God (John 21:19); John's would be different. Jesus did not explain one path by the other. His answer, "what is that to thee? follow thou me," put Peter's focus back where it belonged.

Gill draws the lesson that "it becomes the saints to mind their duty in following Christ, and not concern themselves in things that do not belong to them." Barnes likewise finds here a warning against vain curiosity about others and a call to trust Christ with their lot.