And they began to question one another, which of them it could be who was going to do this (Luke 22:23).
Read John 13:21-30.
Jesus isn't done with Judas yet. He's going to use the reaction of the other disciples to help Judas understand the full nature of the act he is plotting.
The disciples clearly understand Jesus' prediction that one of them will betray Him, but they are utterly dumbfounded. The thought had never crossed their minds that one of their number could be capable of such a hideous act. So they begin to question each other and ask who it is.
It is hard to imagine Judas being completely unaffected as the reactions spread around him. He has to be asking himself, "How does Jesus know? What is He going to do?" He can't possibly fail to realize the great danger he now faces. Jesus has completely turned the tables, and Judas is completely at His mercy. What if Jesus chooses to save Himself by betraying Judas to the other 11?
Jesus wants His traitorous disciple to know how it feels to be betrayed. He walks Judas right to the brink of betrayal. It should be enough to send a shudder through Judas, and a stab of remorse and regret in his heart.
But tragically, Judas refuses to allow the Holy Spirit to bring repentance; instead, he opens his heart wide for Satan. He quickly takes the morsel of bread, and goes off into the night to perform his foul deed. Every Gospel makes it clear that during the meal none of the disciples realized Judas was the one. Jesus was careful to shield and protect him from them, just as Judas should have protected Jesus.
THE PRAYER: Lord Jesus, guard my heart from such cold indifference and unbelief. Move me to sincere repentance and faith that I may always cling to You, my only Savior. Amen.