Matthew 26:22 records the identical reaction of the disciples asking 'Is it I, Lord?', showing synoptic consistency.

John 13:22 shows the disciples looking at each other uncertainly, matching their sorrowful questioning in Mark.

Luke 22:23 specifies they argued among themselves about who would betray, directly paralleling the disciples' confusion.

John 13:26 identifies Judas by the dipped morsel, resolving the disciples' doubt and fulfilling the prediction.