21:1 After these things 1 Jesus shewed himself again to the disciples at the sea of Tiberias; and on this wise shewed he [himself].
(1) In that Christ is not only present here but also eats with his disciples, he gives a most full assurance of his resurrection.
21:7 Therefore that disciple whom Jesus loved saith unto Peter, It is the Lord. Now when Simon Peter heard that it was the Lord, he girt [his] fisher’s a coat [unto him], (for he was naked,) and did cast himself into the sea.
(a) It was a linen garment which prevented him from swimming freely.
21:15 2 So when they had dined, Jesus saith to Simon Peter, Simon, [son] of Jonas, lovest thou me more than these? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my lambs.
(2) Peter by this triple confession is restored into his former position from where he fell by his triple denial: and furthermore it is proclaimed that he is indeed a pastor, who shows his love to Christ in feeding his sheep.
21:17 He saith unto him the b third time, Simon, [son] of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep.
(b) It was appropriate that he that had denied him three times should confess him three times, so that Peter might neither doubt the forgiveness of his grievous sin, nor his being restored to the office of the apostleship.
21:18 3 Verily, verily, I say unto thee, When thou wast young, thou c girdedst thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall d gird thee, and carry [thee] whither thou wouldest e not.
(3) The violent death of Peter is foretold.
21:19 This spake he, signifying by f what death he should glorify God. And when he had spoken this, he saith unto him, Follow me.
(c) Those that took long trips, especially in the east and in those places where the people used long garments, needed to be girded and fastened up.
(d) He meant that kind of girding which is used with captives, when they are bound fast with cords and chains, as one would say, "Now you gird yourself as you think best, to go where you want to go, but the time will come when you will not gird yourself with a girdle, but another will bind you with chains, and carry you where you would not."
(e) Not that Peter suffered anything for the truth of God against his will, for we read that he came with joy and gladness when he returned from the council where he was whipped, but because this will comes not from the flesh, but from the gift of the Spirit who is given to us from above, therefore he shows that there should be a certain striving and conflict or repugnancy, which also is in us, in all our sufferings as touching the flesh.
(f) That is, that Peter would die by a violent death.
21:20 4 Then Peter, turning about, seeth the disciple whom Jesus loved following; which also leaned on his breast at supper, and said, Lord, which is he that betrayeth thee?
(4) We must take heed that while we cast our eyes upon others that we do not neglect that which we are commanded to do.
21:24 5 This is the disciple which testifieth of these things, and wrote these things: and we know that his testimony is true.
(5) The history of Christ is truly and cautiously written: not for the curiosity of men, but for the salvation of the godly.