21 After saying these things, Jesus was troubled in his spirit, and testified, “Truly, truly, I say to you, one of you will betray me.” 22 The disciples looked at one another, uncertain of whom he spoke. 23 One of his disciples, whom Jesus loved, was reclining at table at Jesus’ side, 24 so Simon Peter motioned to him to ask Jesus of whom he was speaking. 25 So that disciple, leaning back against Jesus, said to him, “Lord, who is it?” 26 Jesus answered, “It is he to whom I will give this morsel of bread when I have dipped it.” So when he had dipped the morsel, he gave it to Judas, the son of Simon Iscariot. 27 Then after he had taken the morsel, Satan entered into him. Jesus said to him, “What you are going to do, do quickly.”28 Now no one at the table knew why he said this to him. 29 Some thought that, because Judas had the moneybag, Jesus was telling him, “Buy what we need for the feast,” or that he should give something to the poor. 30 So, after receiving the morsel of bread, he immediately went out. And it was night.
“’Troubled’ is the same verb used of Jesus’ agitation at the grave of Lazarus (11:33) and at the request of the Greeks to see him (12:21). As “the hour” approached, the bitterness of the betrayal Jesus anticipated became known. The desertion by many of his disciples evoked an expression of disappointment; here, the injury was felt more poignantly. The quotation in 13:18, which the author cites as prophetic of Jesus’ feeling, contains in its context an allusion to “my close friend, whom I trusted” (Ps 41:9). Among the sorrows contributing to the agony of the Cross was the voluntary and selfish defection of Judas.”
- Reflect on the fact that Jesus was “troubled in his spirit.” How does this match my view of Jesus? What implication does this have on how I should view acts of betrayal toward Jesus today?
- What may have been the heart of Jesus as he told Judas, “What you are going to do, do quickly”?
- Notice the progression between Satan prompting Judas (v.2) to Satan entering into Judas (v. 27). What steps could Judas have taken to arrest the downward spiral of sin’s increasing hold over his will?
 Frank E. Gaebelein, Expositor’s Bible Commentary CD (Grand Rapids: Zondervan Pub. House, 1992), notes for John chapter 13.