This he said to test him, for he himself knew what he would do. So they gathered them up and filled twelve baskets with fragments from the five barley loaves, left by those who had eaten. Thus, Jesus is replacing the Old Testament way of life. Bread was the staple of the Jewish diet. The Old Testament mentions the unleavened bread, the presence bread, and manna - the bread from heaven.
Bread is seen as life sustaining.
The multiplying of bread and fish shows Jesus' concern for people's physical need, but this was not his main concern. The main concern is that the miracles, or signs, should lead people to deeper faith. One Main Point Jesus is the Bread of Life. On one level, Jesus satisfies our physical hunger. On a deeper level, he is the bread, through which we are led to a deeper level of faith, to participate in God's life.