Analyticae Quaestiones & Responsiones de pane vitae

Christ solidly refuted, when, by calling Himself the Son of man, He testified that His Flesh, hypostatically proper to the almighty λόγος Word, vivifies as an συνεργὸν instrumental co-worker: while the λόγος Word Himself is per se αὐτοζωὴ self-life/life in Himself and naturally vivifies.

So therefore let us establish that, in that holy Supper, Earthly things are perceived by the mouth of the body: Heavenly things by the mouth of the soul, or faith: and that the power of vivifying is by no means separated from the communion of the body and blood of Christ.

But to those who think that the Body and blood of Christ, in, with, or under the bread, are brought into the mouth of the body by the hand of the Minister, and are even eaten orally by the impious, let us propose this Demonstration to be pondered.
Whatever enters into a man from the outside (thus he calls those things which are perceived orally) does not enter into his HEART, but into the BELLY. Mark 7:18-19.
But the Body of Christ and His blood do not enter into the BELLY, but into the HEART. Therefore it is said that Christ dwells in our hearts through faith. Eph. 3:17. And we are said to walk by faith, and not by sight. 2 Cor. 5:7. But faith makes those things that are hoped for to exist. Heb. 11:1.
Therefore the Body of Christ and His Blood are truly perceived, not by the mouth, but by faith.

Written at Basel, on the Kalends of January, in the year 1587.