In this section, Jesus lays out perhaps the most difficult revelation of His ministry. Thus far he has responded to questions from the Jews in Capernaum regarding the bread, the amazing bread that Jesus had miraculously produced by prayer a few days earlier. This bread that came down from heaven, had been a life-changing experience for those who had been there that day, and was continuing to amaze those who had heard about it and were hoping for a repeat performance from this man with the divine connection.
That is all Jesus was to the masses and the Jews in the synagogue in Capernaum - a miracle man with miracle powers. But, to their amazement, Jesus emphasizes not what He can do, but where He came from and Who and What He is. He is the bread that came down from heaven, not given by the power of a man. This is the sign that Jesus used to awaken His audience and serve as a call for belief. The nature of the miracle points only to the miracle of the man Jesus, the Word, the Son of God, the bread of heaven.
