The manna by which the Chosen People were nourished in the wilderness was a figure of the Eucharist, the spiritual food by which we are sustained and illuminated in the desert of this world.

Jesus, in His discourse on the Bread of Life in the synagogue of Capharnaum (John 6) proclaimed that He was the true manna, the "food that endures for life everlasting," the "Bread of God which came down from heaven and which gives life to the world" (John 6: 27, 33).

... Jesus makes clear that the Bread of Life is first of all His own Person, then His communication of Himself to us in two forms: in the Scriptures, the "word of God," and in the Eucharist.

The whole work of man in this life is to find God. We are not to labor for perishing food, but for the food of eternal life, the Logos. "This is the work of God, that you believe in Him Whom He has sent (v. 29). The Jews challenge Him to prove He is the Messiah, by working a miracle. Moses prayed to God and manna was given to feed the people of Israel in the desert. What sign would Jesus give, to prove His claims? Jesus answers that what they need is not more external signs from Him, but faith in the depths of their own hearts. They have already seen a miracle in which He fed five thousand men with a few barley loaves and some little fishes: but that has done nothing to open their eyes: "I am the Bread of Life" says Jesus. "He who comes to me shall not hunger and he who believes in me shall never thirst. But I have told you that you have seen me and do not believe" (v. 35-36).

The Living Bread
Thomas Merton