John 21:1-14
The disciple whom Jesus loved said to Peter, “It is the Lord.”

After this, Jesus manifested himself again to the disciples at the Sea of Tiberias. And he manifested himself in this way.
These were together: Simon Peter and Thomas, who is called the Twin, and Nathanael, who was from Cana of Galilee, and the sons of Zebedee, and two others of his disciples.
Simon Peter said to them, “I am going fishing.” They said to him, “And we are going with you.” And they went and climbed into the boat. And in that night, they caught nothing.
But when morning arrived, Jesus stood on the shore. Yet the disciples did not realize that it was Jesus. Then Jesus said to them, “Children, do you have any food?” They answered him, “No.”
He said to them, “Cast the net to the right side of the boat, and you will find some.” Therefore, they cast it out, and then they were not able to draw it in, because of the multitude of fish.
Therefore, the disciple whom Jesus loved said to Peter, “It is the Lord.” Simon Peter, when he had heard that it was the Lord, wrapped his tunic around himself, (for he was naked) and he cast himself into the sea.
Then the other disciples arrived in a boat, (for they were not far from the land, only about two hundred cubits) dragging the net with the fish.
Then, when they climbed down to the land they saw burning coals prepared, and fish already placed above them, and bread.
Jesus said to them, “Bring some of the fish that you have just now caught.” Simon Peter climbed up and drew in the net to land: full of large fish, one hundred and fifty-three of them. And although there were so many, the net was not torn.
Jesus said to them, “Approach and dine.” And not one of them sitting down to eat dared to ask him, “Who are you?” For they knew that it was the Lord. And Jesus approached, and he took bread, and he gave it to them, and similarly with the fish.
This was now the third time that Jesus was manifested to his disciples, after he had resurrected from the dead.
What do the Fathers say?
St John Chrysostom
Portion of Homily 87 on the Gospel of John
John 21:1
After these things, Jesus manifested Himself again to the disciples at the sea of Tiberias.
Do you see that He remains not with them continually, nor as before? He appeared, for instance, in the evening, and went away; then after eight days again once, and again went away; then after these things by the sea, and again with great terror. But what is the, manifested?
From this it is clear that He was not seen unless He condescended, because His body was henceforth incorruptible, and of unmixed purity. But why has the writer mentioned the place? To show that he had now taken away the greater part of their fear, so that they now ventured forth from their dwelling, and went about everywhere. For they were no longer shut up at home, but had gone into Galilee, avoiding the danger from the Jews. Simon, therefore, comes to fish. For since neither was He with them continually, nor was the Spirit yet given, nor they at that time yet entrusted with anything, having nothing to do, they went after their trade.and this same they did by night, because they were greatly afraid.
John 21:2
There were together Simon Peter, and Thomas, and Nathanael, (he that was called by Philip,) and the sons of Zebedee, and two others.
Having then nothing to do, they went to their fishing, and this same they did by night, because they were greatly afraid. This Luke also mentions; but this is not the same occasion, but a different one. And the other disciples followed, because they were henceforth bound to one another, and at the same time desired to see the fishing, and to bestow their leisure well. As they then were laboring and wearied, Jesus presents Himself before them, and does not at once reveal Himself, so that they enter into converse with Him. He therefore says to them,
John 21:5
Have you any meat ?
For a time He speaks rather after a human manner, as if about to buy something from them. But when they made signs that they had none, He bade them cast their nets to the right; and on casting they obtained a haul. But when they recognized Him, the disciples Peter and John again exhibited the peculiarities of their several tempers. The one was more fervent, the other more lofty; the one more keen, the other more clear-sighted. On this account John first recognized Jesus, Peter first came to Him. For no ordinary signs were they which had taken place. What were they? First, that so many fish were caught; then, that the net did not break; then, that before they landed, the coals had been found, and fish laid thereon, and bread. For He no longer made things out of matter already subsisting, as, through a certain dispensation, He did before the Crucifixion. When therefore Peter knew Him, he threw down all, both fish and nets, and girded himself. Do you see his respect and love? Yet they were only two hundred cubits off; but not even so could Peter wait to go to Him in the boat, but reached the shore by swimming. What then does Jesus?
John 21:12
Come, He says, dine. And none of them dared ask Him.
For they no longer had the same boldness, nor were they so confident, nor did they now approach Him with speech, but with silence and great fear and reverence, sat down giving heed to Him.
For they knew that it was the Lord.
And therefore they did not ask Him, Who are You? But seeing that His form was altered, and full of much awfulness, they were greatly amazed, and desired to ask somewhat concerning it; but fear, and their knowledge that He was not some other, but the Same, checked the enquiry, and they only ate what He created for them with a greater exertion of power than before. For here He no more looks to heaven, nor performs those human acts, showing that those also which He did were done by way of condescension. And to show that He remained not with them continually, nor in like manner as before, It says that,
John 21:14
This was the third time that Jesus appeared to them, after that He arose from the dead.
And He bids them to bring of the fish, to show that what they saw was no appearance. But here indeed it says not that He ate with them, but Luke, in another place, says that He did; for He was eating together with them. (Acts 1:4) But the, how, it is not ours to say; for these things came to pass in too strange a manner, not as though His nature now needed food, but from an act of condescension, in proof of the Resurrection.
Source: Extract from St John Chrysostom’s homily from Newadvent.org
