Jesus Holds the Cup at the Passover MealBible World

Mark 14:20

And he answered and said unto them, It is one of the twelve, that dippeth with me in the dish.

The dipping in the dish marked the betrayer as one of the twelve, so the treachery came from inside the circle of close discipleship and shared fellowship and communion. The sign pointed to Judas, though the other disciples did not suspect him. The words were spoken at the Passover supper and meal, when Jesus was troubled and weighed down and depressed under the cloud of coming calamity as He announced that one of the favored twelve would betray Him.

That announcement filled the disciples with amazement and consternation and fear and self-distrust. They examined their own hearts and searched one another's faces and asked one by one with painful feeling whether it was themselves. The identification was given as a private answer to John's distressed question. Amid the confusion and astonishment Judas at first did not hear it, then his silence drew all eyes to him, and when he asked in order to escape scrutiny Jesus confirmed his guilt with solemn discovery.

The identification shows Jesus already knew who would betray Him, proving that all of Judas's thoughts were known to Him. It was final convincing proof of His divinity and divine foresight and Messiahship, and the betrayal itself took place within what Scripture had foretold. The disclosure was an act of touching forbearance and infinite mercy with a twofold purpose. It gave Judas one last chance to repent and turn back and escape the betrayer's doom, which he refused and did not use before his treachery was consummated. It also gave the disciples crowning evidence beforehand by revealing the hidden purpose of Judas before it happened, so they would believe and would not think their Master lacked foresight and was deceived and surprised into the hands of a mob, so their faith would be strengthened during His humiliation, and so they would remember the announced woe when Judas came to his dreadful end.