Jesus said that blessedness comes through obedience (v. 17). Then He announces that one of the disciples would receive no blessedness. This is prophesied in http://ref.ly/Ps41.9. The selection of Judas as the betrayer is no accident. The betrayer would be one of Jesus’ own. http://ref.ly/Jn6.70f-71. David was betrayed by his trusted table companion Ahithophel, who hung himself. 2 Samuel 16:20-17:3, 23. Judas is Jesus’ close companion. He betrays Jesus and then hangs himself. Although Judas’ deed was foreknown by God, he was fully culpable. The fact that Jesus knew this ahead of time let the disciples know that Jesus had been sent by God. Note John 13:19 and John 14:29.
This verse begins with the word “verily.” It is often translated by commentaries as “surely, surely” and “truly, truly.” The disciples shall represent Jesus. Anyone who accepted the disciples accepted Jesus Christ.
This fact caused Jesus to be troubled in His spirit. The word “troubled” from the Greek word etarachthe, which means, “stirred or agitated.” It is the same word used of Jesus in John 11:33 and John 12:27. The human side of Jesus was troubled by the action that Judas would soon do. Betrayal hurts especially when it is known in advance. Jesus sensed the spiritual hardness and deadness which sin had produced in Judas. “The word testified and the formula I tell you the truth stress the solemn announcement of Jesus’ words.” [The Bible Knowledge Commentary NT – Front Matter, page 322]
This act is beyond comprehension. Judas had covered his tracks well. None of the other disciples suspected him. Peter, because of his emotions, wanted to deal with the traitor. Luke mentioned that the disciples had two swords! They were ready for battle! John 22:38, 49-50. The disciple whom Jesus loved is John, the author of this gospel. It should be noted that John and Judas were reclining next to Jesus. Peter’s position at the table was not near enough to Jesus to ask Him privately. He motioned to John to ask Jesus whom He meant. Can you imagine the upheaval that arose among the disciples? None of them calmly accepted this fact. Who, among them, would have such an act in their minds?