20 Make sure you get this right: Receiving someone I send is the same as receiving me, just as receiving me is the same as receiving the One who sent me."
21 After he said these things, Jesus became visibly upset, and then he told them why. "One of you is going to betray me." 22 The disciples looked around at one another, wondering who on earth he was talking about. 23 One of the disciples, the one Jesus loved dearly, was reclining against him, his head on his shoulder. 24 Peter motioned to him to ask who Jesus might be talking about. 25 So, being the closest, he said, "Master, who?" 26 Jesus said, "The one to whom I give this crust of bread after I've dipped it." Then he dipped the crust and gave it to Judas, son of Simon the Iscariot. 27 As soon as the bread was in his hand, Satan entered him. "What you must do," said Jesus, "do. Do it and get it over with." 28 No one around the supper table knew why he said this to him. 29 Some thought that since Judas was their treasurer, Jesus was telling him to buy what they needed for the Feast, or that he should give something to the poor. 30 Judas, with the piece of bread, left. It was night.
Matthew Henry's Commentary on John 13:20-30
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.