Jesus Reveals Himself
This is the third time that Jesus reveals Himself to the disciples. Why were they fishing if they were disciples? In this period of uncertainty they gravitated towards that which was familiar and they felt comfortable with, fishing. Although the night was an empty catch, morning came. They cast the net on the other side and caught a large catch of fish. Additional Jesus had prepared breakfast for them. Just like the night before His crucifixion when He washed the disciples feet He here demonstrates the role of the servant.
In the discourse with Peter Jesus ask him three times do you love me? Notice the parallel to Peter's three denials. He wanted Peter to know that he was forgiven and so to speak the score board was reset. He then told Peter what would happen to him when he was old. Although it may not be what one wishes to hear, it was an affirmation that Peter would remain faithful from here on and go the distance.