21 When Jesus had said this, he was troubled in spirit, and testified, “Most certainly I tell you that one of you will betray me.” 22 The disciples looked at one another, perplexed about whom he spoke. 23 One of his disciples, whom Jesus loved, was at the table, leaning against Jesus’ breast. 24 Simon Peter therefore beckoned to him, and said to him, “Tell us who it is of whom he speaks.” 25 He, leaning back, as he was, on Jesus’ breast, asked him, “Lord, who is it?” 26 Jesus therefore answered, “It is he to whom I will give this piece of bread when I have dipped it.” So when he had dipped the piece of bread, he gave it to Judas, the son of Simon Iscariot. 27 After the piece of bread, then Satan entered into him.
Then Jesus said to him, “What you do, do quickly.” 28 Now no man at the table knew why he said this to him. 29 For some thought, because Judas had the money box, that Jesus said to him, “Buy what things we need for the feast,” or that he should give something to the poor. 30 Therefore, having received that morsel, he went out immediately. It was night.
Matthew Henry's Commentary on John 13:21-30
Commentary on John 13:18-30
(Read John 13:18-30)
Our Lord had often spoken of his own sufferings and death, without such trouble of spirit as he now discovered when he spake of Judas. The sins of Christians are the grief of Christ. We are not to confine our attention to Judas. The prophecy of his treachery may apply to all who partake of God's mercies, and meet them with ingratitude. See the infidel, who only looks at the Scriptures with a desire to do away their authority and destroy their influence; the hypocrite, who professes to believe the Scriptures, but will not govern himself by them; and the apostate, who turns aside from Christ for a thing of naught. Thus mankind, supported by God's providence, after eating bread with Him, lift up the heel against Him! Judas went out as one weary of Jesus and his apostles. Those whose deeds are evil, love darkness rather than light.