The Most Holy Body And Blood Of Our Lord

Now as Jesus Christ appeared to his holy Apostles in true flesh,
so now he shows himself to us in consecrated bread; and as with their physical sight they saw only his flesh, but contemplating him with the eyes of faith, believed that he was God, so too, now, though we see bread and wine with the eyes of our body, we should see and firmly believe that it is his Most Holy Body and Blood, living and true.

St. Francis
Admonition 1