I am the living bread which came down from heaven: if any man eat of this bread, he shall live forever: and the bread that I will give is my flesh, which I will give for the life of the world.
All Commentaries on John 6:51 Go To John 6
Augustine of Hippo
AD 430
Our Lord pronounces Himself to be bread, not only in respect of that Divinity, which feeds all things, but also in respect of that human nature, which was assumed by the Word of God: And the bread, He says, that I will give is My flesh, which I will give for the life of the world.
But when does flesh receive the bread which He calls His flesh? The faithful know and receive the Body of Christ, if they labor to be the body of Christ. And they become the body of Christ, if they study to live by the Spirit of Christ: for that which lives by the Spirit of Christ, is the body of Christ. This bread the Apostle sets forth, where he says, We being many are one body. O sacrament of mercy, O sign of unity, Obond of love! Whoso wishes to live, let him draw nigh, believe, be incorporated, that he maybe quickened.