Some early manuscripts containing the text of this chapter are:
Papyrus 66
Papyrus 109
Codex Vaticanus
Codex Sinaiticus
Papyrus 122
Codex Bezae
Codex Alexandrinus
Papyrus 59
Appendage?
Verse 1
In the previous chapter of John's Gospel, the text summarizes the many signs which Jesus performed for his followers, not all of which could be recorded in the Gospel. John 21 begins with the 'Johannine transition', After these things... which is used frequently in the Fourth Gospel, leading some scholars to suggest that John 21 was appended in the same way as Mark 16:9–20. Peter's ecclesiastical role is emphasized, but this is similar to Peter's commissioning in John 1. Westcott proposed a theory that the author simply decided to add an additional incident at some time after writing the book, but before final publication. Donald Guthrie writes:
It is unlikely that another author wrote this section since there are several points of contact in it with the style and language of previous chapters...
The Church Father Tertullian wrote, "And wherefore does this conclusion of the gospel affirm that these things were written unless it is that you might believe, it says, that Jesus Christ is the son of God?", which describes the end of Chapter 20, not Chapter 21. However, no existing manuscript of the Gospel omits this chapter.
Manuscript evidence
The Nestle-Aland Novum Testamentum Graece as well as major translations of the New Testament retain this chapter in their editions as original. In an essay, contributed on behalf of scholars unconvinced of any decisive sense of "originality" to John 21, Felix Just wrote: "We do not possess any ancient manuscript of John that actually ends at." In other words, ancient manuscripts that contain the end of John 20 also contain text from John 21. So if John 21 is an addition, it was so early and so widespread, that no evidence of the prior form has survived. This should however be balanced against the tendency for the first and last pages of codices to be lost: there are just four papyrus witnesses to John 20–21, only three of which date from the 4th century or earlier. Novum Testamentum Graece and the United Bible Societies provide the critical text for John 21. In 2006 one 4th-century Sahidic papyrus manuscript came to light that it may end at 20:31, but this is not conclusive due to its fragmentary state.
The description of the "beloved disciple's" fate is presented as an aside to Peter. Jesus says that it is not Peter's concern, even if Jesus should wish that that disciple remain alive until the end of time. The following verse clarifies that Jesus did not say "This disciple will not die", but that it was not for Peter to know. The last appearance of the 'Disciple whom Jesus loved' in this Gospel, together with his first appearance in chapter 1 form a literary "inclusio of eyewitness testimony" to privilege this witness over Peter's, not to denigrate Peter's authority, but rather to claim a distinct qualification as an 'ideal witness' to Christ, because he survives Peter and bears his witness after Peter. The inclusio also reinforces the Beloved Disciple’s unique status among the disciples: He has followed and remained with Jesus from beginning to end. Bauckham notes the occurrence of at least two specific words in the narratives of both the first and the last appearance of this disciple: "to follow" and "to remain/stay". In the first chapter verse it is stated that "Jesus turned, and seeing them following , said to them, "What do you seek?"", then in verse they "remained with Him that day". In John 21, the last appearance of the 'Disciple whom Jesus loved' is indicated using similar words: in verse it is written that "Peter, turning around, saw the disciple whom Jesus loved following ", then in verse "Jesus said to him , "If I will that he remain till I come, what is that to you?" The appearances are also close to Peter's, as the first one, along with Andrew, happened just before Peter's, who was then given the name 'Cephas', and the last one, just after Jesus' dialogue with Peter, acknowledging the significance of Peter's testimony within "the Petrine's inclusio", which is also found in the Gospel of Mark and Luke.
Verses 24–25
The chapter is closed by two verses referring to the author of the gospel in the third person.