23 And having taken the chalice, giving thanks, he gave it to them. And they all drank of it.
Pseudo-Jerome: “He gave it to them.” For we are saved by the grace of the Lord, not by our own deserts.
Bede: The wine of the Lord’s cup is mixed with water, because we should remain in Christ and Christ in us. For on the testimony of John, the waters are the people [Rev 17:15], and it is not lawful for any one to offer either wine alone, or water alone, lest such an oblation should mean that the head may be severed from the members, and either that Christ could suffer without love for our redemption, and that we can be saved or be offered to the Father without His Passion.
Chrysostom: Christ offered His Blood to him who betrayed Him, that he might have remission of his sins, if he had chosen to cease to be wicked.
Pseudo-Jerome: Judas therefore drinks and is not satisfied, nor can he quench the thirst of the everlasting fire, because he unworthily partakes of the Mysteries of Christ. There are some in The Church whom the Sacrifice does not cleanse, but their foolish thought draws them on to sin, for they have plunged themselves in the stinking slough of cruelty.
Chrysostom: 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 own nature, 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.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. II (London: Rivington, 1842).