john 13:22 Then the disciples looked one on another, doubting of whom he spake. - Free Bible Online

      22. the disciples looked one on another, doubting of whom he spake--Further intensely interesting particulars are given in the other Gospels: (1) "They were exceeding sorrowful" (Mt 26:22). (2) "They began to inquire among themselves which of them it was that should do this thing" (Lu 22:23). (3) "They began to say unto Him one by one, Is it I, and another, Is it I?" (Mr 14:19). Generous, simple hearts! They abhorred the thought, but, instead of putting it on others, each was only anxious to purge himself and know if he could be the wretch. Their putting it at once to Jesus Himself, as knowing doubtless who was to do it, was the best, as it certainly was the most spontaneous and artless evidence of their innocence. (4) Jesus, apparently while this questioning was going on, added, "The Son of man goeth as it is written of Him, but woe unto that man by whom the Son of man is betrayed! It had been good for that man if he had not been born" (Mt 26:24). (5) "Judas," last of all, "answered and said, Lord, is it I?" evidently feeling that when all were saying this, if he held his peace, that of itself would draw suspicion upon him. To prevent this the question is wrung out of him, but perhaps, amidst the stir and excitement at the table, in a half-suppressed tone as we are inclined to think the answer also was--"Thou hast said" (Mt 26:25), or possibly by little more than a sign; for from Joh 13:28 it is evident that till the moment when he went out, he was not openly discovered.

JFB.