John Chrysostom
Catena Aurea · Markusevangelium 14
And as they did eat, Jesus took bread, and blessed, and brake it, and gave to them, and said, Take, eat: this is my body. And he took the cup, and when he had given thanks, he gave it to them: and they all drank of it. And he said unto them, This is my blood of the new testament, which is shed for many. Verily I say unto you, I will drink no more of the fruit of the vine, until that day that I drink it new in the kingdom of God.
(ubi sup.) Let there not be therefore a Judas at the table of the Lord; this sacrifice is spiritual food, for as bodily food, working on a belly filled with humours which are opposed to it, is hurtful, so this spiritual food if taken by one polluted with wickedness, rather brings him to perdition, not by its ownnature, but through the fault of the recipient. Let therefore our mind be pure in all things, and our thought pure, for that sacrifice is pure. There follows: And he said unto them, This is my blood of the New Testament, which is shed for many.