Complaining. The story of the Hebrew people in the 40 years of the dessert is a story of complaints. Poor Moses had to go before God begging for release from their complaints. It was in answer to this that God provides the manna and water from the rock. John reverses the process in his Gospel story. Jesus promises the bread of life and this provokes the complaints.
Jesus' teaching is based on the Wisdom books of the Old Testament. It is divine wisdom that feeds the hunger of the heart. "To hear the teaching of the Father and learn from it is to come to me."
"Everyone who believes has eternal life."
"I am the bread of life." "This is the bread that comes down from heaven, so that a man may eat it and not die."
The concluding verse opens up a whole new chapter for next week. Jesus introduces a whole new aspect of Eucharistic teaching. "Anyone who eats this bread will live forever; and the bread that I will give is my flesh, for the life of the world."
Here the bread is identified with Jesus' flesh, the crucified on the Cross, and given prophetically at the Last Supper.