Of the Mystical Feast of the Altar of the Lord

In very truth it is a marvelous thing that God rained manna on the fathers, and fed them with daily food from heaven; so that it is said, “So man did eat angels’ food.” But yet all those who ate that food died in the wilderness, but that food which you receive, that living Bread which came down from heaven, furnishes the substance of eternal life; and whosoever shall eat of this Bread shall never die, and it is the Body of Christ.

Now consider whether the bread of angels be more excellent or the Flesh of Christ, which is indeed the body of life. That manna came from heaven, this is above the heavens; that was of heaven, this is of the Lord of the heavens; that was liable to corruption, if kept a second day, this is far from all corruption, for whosoever shall taste it holily shall not be able to feel corruption. For them water flowed from the rock, for you Blood flowed from Christ; water satisfied them for a time, the Blood satiates you for eternity. The Jew drinks and thirsts again, you after drinking will be beyond the power of thirsting; that was in a shadow, this is in truth.

If that which you so wonder at is but shadow, how great must that be whose very shadow you wonder at. See now what happened in the case of the fathers was shadow: “They drank, it is said, of that Rock that followed them, and that Rock was Christ. But with many of them God was not well pleased, for they were overthrown in the wilderness. Now these things were done in a figure concerning us.” You recognize now which are the more excellent, for light is better than shadow, truth than a figure, the Body of its Giver than the manna from heaven.

Ambrose of Milan, On the Mysteries 8.47–49