“What Thou Dost, Do Quickly”

Fr. Scott Haynes

Christ, Judas, and the Permission of Darkness at the Last Supper

At the Last Supper, one of the most haunting moments in all the Gospel unfolds in a few brief lines. Jesus identifies the betrayer, hands him the morsel, and then says,

“That which thou dost, do quickly.”[1]

The scene is at once intimate and terrible. The table of fellowship has become the threshold of betrayal. The hand that receives from Christ is the hand that will soon deliver Him over.

Yet the mystery of this moment is deeper still. St. John does not merely tell us that Judas resolves to betray the Lord. He says something even more chilling:

“And after the morsel, Satan entered into him.”[2]

The betrayal is human, but it is not merely human. Judas acts freely and wickedly, but behind his act stands the ancient enemy. This raises a searching theological question: when Christ says, “What thou dost, do quickly,” is He speaking only to Judas, or is there also, in a deeper sense, an address to Satan who has entered him?

The most immediate answer is that Christ is speaking to Judas. The Gospel’s plain sense requires that. Judas is the visible actor. Judas is morally responsible. Judas rises from the table and goes out into the night. The Fathers do not allow us to dissolve his responsibility into demonic influence, as though he had simply become a puppet. Rather, they emphasize that Satan gained fuller entrance because Judas had already opened the door through sin.

St. Augustine states this with great clarity. Commenting on John 13, he writes:

“It was after this bread, then, that Satan entered into the Lord’s betrayer, that, as now given over to his power, he might take full possession of one into whom before this he had only entered in order to lead him into error.”[3]

Judas did not become guilty only when Satan entered him. The devil entered more fully because Judas had long been consenting inwardly to darkness. Earlier in the Gospel, Judas is already exposed as corrupt, for St. John tells us that he was a thief.[4]

St. John Chrysostom develops the same point with psychological precision. Satan, he says, does not usually seize all at once, but works gradually, testing, suggesting, probing the will. Speaking of Judas, Chrysostom says that the devil, “after having tried him in the beginning, and assailed him quietly, after that he saw him prepared to receive him, he thenceforth wholly breathed himself into him.”[5] In other words, the catastrophe at the Supper is not a sudden accident. It is the culmination of many earlier acts of resistance to grace.

St. Cyril of Alexandria is equally forceful. He warns that evil gains mastery by degrees. Satan was first a whisperer, then a counselor, and at last became the tyrant of Judas’s heart. Cyril writes:

“For no longer has he Satan merely as a counsellor, but he takes him now to be master of his whole heart and absolute dominator of his thoughts.”[6]

It is a fearful lesson. A sin tolerated becomes a habit; a habit indulged becomes a chain.

And yet, although Christ directly addresses Judas, several Fathers perceive in the Lord’s words a depth that reaches beyond Judas alone. Christ does not speak as one overtaken by events. He speaks as the sovereign Lord, calmly permitting the betrayal to move toward its appointed hour. Here the comparison with Job becomes illuminating. In the Book of Job, Satan can do nothing without divine permission. He appears before God, asks leave to test the just man, and is given only measured scope.

“Behold, he is in thy hand: but yet save his life.”[7]

Satan is active, but he is not sovereign. He can wound, tempt, and afflict, but only within limits set by God.

The same theology appears in the Fathers. Chrysostom, reflecting on satanic activity more broadly, declares: “For he will not approach to us, except God permit him; for if he dared not to enter into the herd of swine, except by God’s permission, how much less into men’s souls. But God does permit him, either chastening or punishing us, or making us more approved, as in the case of Job.”[8] This is a principle of great importance. The devil is not free in the way God is free. He is always a creature, never a rival deity. Even his malice remains under the mysterious governance of providence.

That is why Christ’s words to Judas are so arresting. They do not sound like the language of fear or helplessness. They sound like the language of mastery. St. Leo the Great captures this magnificently:

“This is the voice not of command but of permission, and not of fear but of readiness.”[9]

Leo goes on to explain that Christ “puts no hindrance in the way of the traitor” because He is carrying out the Father’s will for the redemption of the world.[10] Christ is not endorsing the crime. He is permitting it to move forward because the hour of His Passion, long foreknown and freely embraced, has come.

St. Augustine says much the same in a briefer and sharper way:

“He did not command the crime, but foretold evil to Judas, and good to us.”[11]

That sentence is essential. Christ does not command wickedness as wickedness. He does not bless betrayal. But neither is He surprised by it, overpowered by it, or driven along by it. The traitor thinks he is acting; in reality, he is only moving within the bounds of an hour that belongs wholly to Christ.

Indeed, St. Cyril of Alexandria comes very near the interpretation you proposed. While preserving Judas’s role, he hears in Christ’s saying a deeper address to the devil who is using Judas as his instrument. Cyril comments that Christ speaks as though saying:

“That work of thine, O Satan, whereof thou alone knowest, and which is ever dear to thee, see that thou do quickly.”[12]

Cyril even adds that the Lord thus urges Satan forward toward his own defeat, since by hurrying the Passion he is unwittingly helping to bring about the destruction of his own tyranny.[13]

This is a remarkable patristic insight. It does not cancel the literal sense of the Gospel, in which Jesus speaks to Judas. But it does show that the Fathers could hear in the Lord’s words a second depth. Christ addresses the human betrayer standing before Him, but He does so in full awareness of the dark spiritual power now pressing through the man. The Lord’s word falls upon Judas, yet it also sounds through him and against the invisible enemy.

That reading harmonizes beautifully with the Gospel of St. John as a whole. Jesus is never portrayed as trapped by hostile forces. He is not caught in a machinery of betrayal beyond His control. Again and again, John shows that Christ goes freely to His Passion.

“No man taketh it away from me: but I lay it down of myself.”[14]

The Cross is not finally something done to Him apart from His will. It is something He accepts, offers, and transforms. As St. Peter later preaches, Christ was “delivered up, by the determinate counsel and foreknowledge of God,” though those who crucified Him did so with “wicked hands.”[15] Divine providence and human guilt stand together. God wills the saving sacrifice; men will the crime. The same event contains both, but not in the same way.

Here lies the terrible irony of Judas’s betrayal. Satan imagines he is advancing his triumph. Judas imagines he is securing his own design. The chief priests imagine they are silencing Jesus. But all alike are moving, knowingly or unknowingly, toward the very event by which Christ will break the kingdom of darkness.

“Now shall the prince of this world be cast out.”[16]

What appears to hell as victory is in fact its ruin.

The final note of the scene makes this even more solemn. St. John says:

“He therefore having received the morsel, went out immediately. And it was night.”[17]

That night is not merely atmospheric. It is spiritual. Judas goes out into darkness because darkness has already entered him. Augustine’s terse comment is unforgettable:

“And he that went out was himself the night.”[18]

The words are severe, but they fit the gravity of the moment. Judas has become, by his own consent, the bearer of interior darkness.

Yet even here the darkness does not reign. Christ remains serene. Christ remains sovereign. Christ remains Lord of the hour. The devil can enter Judas, but he cannot enter history as master. He can stir betrayal, but he cannot seize the throne of providence. He can hasten the Passion, but only so that through the Passion he himself may be cast down. As St. Paul says, Christ in His Cross despoiled “principalities and powers,” triumphing over them.[19]

So, the most careful conclusion is this. In the immediate and literal sense, Jesus says, “What thou dost, do quickly,” to Judas, who remains fully responsible for his betrayal. But the Fathers also allow us to perceive a deeper dimension: Christ’s word falls upon the Satan who has entered Judas, revealing that even infernal malice moves only under divine permission, as in the trial of Job. The Lord does not command evil as evil. He permits it to advance because His own redemptive hour has come. Judas remains guilty; Satan remains malicious; but Christ remains sovereign over both. At the Last Supper, even in the presence of betrayal, the true Master of the scene is still Jesus.

Footnotes

1. John 13:27 (Douay-Rheims).

2. John 13:27 (Douay-Rheims).

3. Augustine, Tractates on the Gospel of John, Tractate 62.2, in Nicene and Post-Nicene Fathers, First Series, vol. 7, trans. John Gibb and James Innes (Buffalo, NY: Christian Literature Publishing Co., 1888), New Advent, accessed March 23, 2026, https://www.newadvent.org/fathers/1701062.htm.

4. John 12:6 (Douay-Rheims).

5. John Chrysostom, Homilies on the Gospel of John, Homily 71.1, in Nicene and Post-Nicene Fathers, First Series, vol. 14, ed. Philip Schaff (Buffalo, NY: Christian Literature Publishing Co., 1889), New Advent, accessed March 23, 2026, https://www.newadvent.org/fathers/240171.htm.

6. Cyril of Alexandria, Commentary on the Gospel of John, on John 13:27, at Catena Bible, accessed March 23, 2026, https://catenabible.com/com/57eb0c76b0d44ee10cfac012.

7. Job 2:6; cf. Job 1:12 (Douay-Rheims).

8. John Chrysostom, Homilies on the Gospel of Matthew, Homily 6.6, in Nicene and Post-Nicene Fathers, First Series, vol. 10, ed. Philip Schaff (Buffalo, NY: Christian Literature Publishing Co., 1888), New Advent, accessed March 23, 2026, https://www.newadvent.org/fathers/200106.htm.

9. Leo the Great, Sermon 58 (On the Passion, VII), chap. 4, in Nicene and Post-Nicene Fathers, Second Series, vol. 12, ed. Philip Schaff and Henry Wace (Buffalo, NY: Christian Literature Publishing Co., 1895), New Advent, accessed March 23, 2026, https://www.newadvent.org/fathers/360358.htm.

10. Ibid.

11. Augustine, Tractates on the Gospel of John, Tractate 62.2, https://www.newadvent.org/fathers/1701062.htm.

12. Cyril of Alexandria, Commentary on the Gospel of John, on John 13:28, at Catena Bible, accessed March 23, 2026, https://catenabible.com/com/57eb0c76b0d44ee10cfac013.

13. Ibid.; see also Cyril of Alexandria, Commentary on the Gospel of John, Book 9, at Tertullian Project, accessed March 23, 2026, https://www.tertullian.org/fathers/cyril_on_john_09_book9.htm.

14. John 10:18 (Douay-Rheims).

15. Acts 2:23 (Douay-Rheims).

16. John 12:31 (Douay-Rheims).

17. John 13:30 (Douay-Rheims).

18. Augustine, Tractates on the Gospel of John, Tractate 62.3, https://www.newadvent.org/fathers/1701062.htm.

19. Colossians 2:15 (Douay-Rheims).