5 Look back to Adam, whence the human race sprung. For how but from him was misery propagated? Whence but from him is this hereditary poverty? Let him then, who in his own body was at one time in despair, now that he is set in Christ's body, say with hope, “My heart is smitten down, and withered like grass”. Deservedly, since all flesh is grass. But how did this happen unto you? “Since I have forgotten to eat my bread.” For God had given His commandment for bread. For what is the bread of the soul?
The serpent suggesting, and the woman transgressing, he touched the forbidden fruit, he forgot the commandment: his heart was smitten as it deserved, and withered like grass, since he forgot to eat his bread. Having forgotten to eat bread, he drinks poison: his heart is smitten, and withered like grass....Now eat that bread which you had forgotten. But this very Bread has come, in whose body you may remember the voice of your forgetfulness, and cry out in your poverty, so that you may receive riches.
Now eat: for you are in His body, who says, “I am the living bread which came down from heaven.” You had forgotten to eat your bread; but after His crucifixion, “all the ends of the earth shall be reminded, and be converted unto the Lord.” After forgetfulness, let remembrance come, let bread be eaten from heaven, that we may live; not manna, as they did eat, and died; that bread, of which it is said, “Blessed are they who hunger and thirst after righteousness.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)