Nearly the whole sixth chapter of the Gospel of John is about bread. It begins with an account of Jesus feeding a huge crowd of people from five loaves and two fish and doing it so lavishly that there are 12 baskets of crumbs left over. Then, after Jesus and his disciples left by boat, the next day the crowd searched and found him on the other side of the lake, but Jesus criticized them: "You're looking for me for the wrong reasons, just because I gave you lots of food yesterday. But that's really not what you need most; you need the food of eternal life." "But what should we do?" they asked. And Jesus replied, "This is the work of God, that you believe in him whom God has sent."

The crowd was not sure about that and challenged Jesus to do an additional miraculous work of some sort to pro…