What does John 13:29 mean?
Judas' role in the inner circle was that of treasurer. At some point in the future, the disciples will learn he was embezzling money for his own use (John 12:4–6). At this moment, the other men have no idea that Judas is a false believer, and has already made plans to betray Jesus (Matthew 26:14–16; John 13:2). Lost amid the chaos of Jesus' emotional prediction (John 13:21), Judas has been confronted and dismissed by Jesus (John 13:26–27; Matthew 26:23–25).Those who heard Jesus telling Judas to "hurry up," or to "act quickly" assume nothing negative. Had Judas simply gotten up and left, it probably would have aroused immediate suspicion. But since he's leaving at Jesus' request—or so it seems—the other men would have presumed he had a good reason. As John explains, the other disciples weren't entirely sure what that task was, but they supposed it was legitimate.
As much as Judas' name has become a synonym for "traitor," it won't be until later this evening when the truth comes out. At this point in time, none of Jesus' followers have reason to suspect anything. Worse, for Peter, Jesus will soon predict Peter's denial (John 13:38). In the minds of the other men, that would have made Peter seem like the betrayer, not Judas!