Mark 14:14-20

and wheresoever he shall enter in, say to the master of the house, The Teacher saith, Where is my guest-chamber, where I shall eat the passover with my disciples? And he will himself show you a large upper room furnished and ready: and there make ready for us. And the disciples went forth, and came into the city, and found as he had said unto them: and they made ready the passover. And when it was evening he cometh with the twelve. And as they sat and were eating, Jesus said, Verily I say unto you, One of you shall betray me, even he that eateth with me. They began to be sorrowful, and to say unto him one by one, Is it I? And he said unto them, It is one of the twelve, he that dippeth with me in the dish.