Albert Barnes Commentary John 6:31

"Our fathers ate the manna in the wilderness; as it is written, He gave them bread out of heaven to eat." — John 6:31 (ASV)

Our fathers. The Jews who were led by Moses through the wilderness.

Did eat manna. This was the name given by the Jews to the food that was provided to them by God on their journey. It literally means, "What is this?" and was the question they asked when they first saw it (Exodus 16:14–15). It was small like frost, the size of coriander seed, and had a sweetish taste like honey. It fell in great quantities and was regarded by the Jews as proof of a continuous miracle during forty years, and was incontestable evidence of God’s intervention in favour of their fathers.

The manna sold in drugstores is a different substance from this. It is obtained from the bark of certain trees in Armenia, Georgia, Persia, and Arabia. It is procured, as resin is, by making an incision in the bark, and it flows out or distils from the tree.

As it is written. The substance of this is written in Psalm 78:24-25.

He gave them. This was regarded as a miraculous intervention on their behalf and an attestation of the divine mission of Moses, and so they commonly said that Moses gave it to them.

Bread from heaven. The word heaven, in the Scriptures, often denotes the region of the air, the atmosphere, or that region in which the clouds are. See Matthew 16:3: The sky (heaven) is red and lowering. Also see Matthew 3:16; Luke 4:15; Luke 5:18.

The Jews, as appears from their writings (see Lightfoot), expected that the Messiah would provide his followers with plenty of delicious food. Just as Moses had provided for the Jews in the wilderness, they supposed that Christ would make provision for the temporal needs of his friends. This was probably the sign they were now desirous of seeing.