50. The next day the crowd that had stayed on the opposite shore of the lake realized that only one boat had been there, and that Jesus had not entered it with his disciples, but that they had gone away alone. Then some boats from Tiberias landed near the place where the people had eaten the bread after the Lord had given thanks. Once the crowd realized that neither Jesus nor his disciples were there, they got into the boats and went to Capernaum in search of Jesus. When they found him on the other side of the lake, they asked him, “Rabbi, when did you get here?” Jesus answered, “I tell you the truth, you are looking for me, not because you saw miraculous signs but because you ate the loaves and had your fill. Do not work for food that spoils, but for food that endures to eternal life, which the Son of Man will give you. On him God the Father has placed his seal of approval.” Then they asked him, “What must we do to do the works God requires?” Jesus answered, “The work of God is this: to believe in the one he has sent.” So they asked him, “What miraculous sign then will you give that we may see it and believe you? What will you do? Our forefathers ate the manna in the desert; as it is written: ‘He gave them bread from heaven to eat.” Jesus said to them, “I tell you the truth, it is not Moses who has given you the bread from heaven, but it is my Father who gives you the true bread from heaven. For the bread of God is he who comes down from heaven and gives life to the world.” “Sir,” they said, “from now on give us this bread.” Then Jesus declared, “I am the bread of life. He who comes to me will never go hungry, and he who believes in me will never be thirsty. But as I told you, you have seen me and still you do not believe. I tell you the truth, he who believes has everlasting life. I am the bread of life. Your forefathers ate the manna in the desert, yet they died. 50. But here is the bread that comes down from heaven, which a man may eat and not die. (John, 6: 22 to 36 and 47 to 50).
51. In the first passage, Jesus, by recalling the effect previously produced, gives us clearly to understand that he was not acting with material bread; otherwise the comparison which he established with the yeast of the Pharisees had been without object. “Don’t you remember the five loaves for the five thousand, and how many basketfuls you gathered? Or the seven loaves for the four thousand, and how many basketfuls you gathered? How is it you don’t understand that I was not talking to you about bread? But be on your guard against the yeast of the Pharisees and Sadducees.” This reproach was given them for having had a material idea of the multiplication. The act had been extraordinary enough in itself to have struck the imagination of his disciples, who however appeared not to have remembered it.
This idea is set forth no less clearly from the speech of Jesus upon the bread from heaven, or manna, in which he tries to make them comprehend in the true sense the value of spiritual nourishment. “Work,” said he, “not for food that spoils, but for food that endures to eternal life, which the Son of Man will give you.” This nourishment is his word, which is the bread descended from heaven, and which gives life to the world. “I am the bread of life,” said he: “he who comes to me will never go hungry, and he who believes in me will never be thirsty.”
But these distinctions were too subtle for these rough natures, who could comprehend only tangible things. The manna which had fed their ancestors was the true bread from heaven to them: there was the miracle. If, then, the act of producing bread had taken place materially, why should these same men, for whose profit it was produced a few days before, say to Jesus: “What miraculous sign then will you give that we may see it and believe you? What will you do?” It is evident they understood miracles to be the mighty works which the Pharisees demanded; i.e., signs from heaven as commanded with the wand of an enchanter. Those which Jesus did were too simple, and did not depart enough from the laws of nature. The cures even were not sufficiently extraordinary. The spiritual miracles were not material enough for them.