Mateus 26:25

Then Judas, which betrayed him... — The words appear to have been spoken in the spirit of reckless defiance, which St. John indicates by saying that “after the sop Satan entered into him” (João 13:27). Did his Master (he calls Him by the wonted title of honour, Rabbi) indeed know his guilt? It would appear from St. John’s narrative (João 13:29) that the dread answer, “Thou hast said;” was not heard by all. All that they did hear was the command, “What thou doest, do quickly;” and some at least, probably the rest who were not in the secret of the signal, thought that that command referred to some matter connected with his customary work as the bursar of the company. He was to buy what was needed for the feast (i.e., probably, the customary solemn meal, or Chagigah, of the day that followed on the Paschal Supper), or to give alms to the poor. He, however, understood the meaning of the words, and straightway went out (João 13:27). It follows, from this view of the sequence of events, that though he had eaten bread with his Master, he did not partake of the bread and the cup that were to be the signs of the New Covenant. At this stage St. John inserts the words as to the new commandment, “that ye should love another,” which was embodied in that act of fellowship.