And had rained down manna upon them to eat - Exodus 16:4-5, Exodus 16:14; Numbers 11:7-9. Compare the notes at John 6:31.
And had given them of the corn of heaven - Food that seemed to come down from heaven. The reference here is to the manna, and it is called corn in the sense that it was food, or that it supplied the place of grain. It may also have been called corn from its resemblance to grain. See Exodus 16:31.

The corn of heaven - The manna. It fell about their camp in the form of seeds; and as it appeared to come down from the clouds, it was not improperly termed heavenly corn, or heavenly grain, דגן שמים degan shamayim. The word shamayim is frequently taken to express the atmosphere.

And had rained down manna upon them to eat,.... So called, either from "manah", which signifies to prepare, appoint, and distribute, because this was food prepared of God for the Israelites without them, and was their provision, their appointed portion, and which was daily distributed to them in measure; or from the words , "man hu", what is it? which they used at first sight of the manna, they not knowing what it was, and hence called it "man"; or "manna"; this the Lord rained down from heaven, as he promised he would, that they might have food to eat; see Exodus 16:4.
and had given them of the corn of heaven; bread corn springs out of the earth, but this was corn from heaven, very unusual and wonderful; this greatly aggravated the unbelief of the Israelites, and shows their great ingratitude, that after all this they should disbelieve the Lord, and not trust in his salvation; the manna was a type of Christ, who is called the hidden manna, 1-Corinthians 10:3; see Gill on John 6:32.