Theophylact of Ohrid
Catena Aurea · Markusevangelium 14
And the first day of unleavened bread, when they killed the Passover, his disciples said unto him, Where wilt thou that we go and prepare that thou mayest eat the Passover? And he sendeth forth two of his disciples, and saith unto them, Go ye into the city, and there shall meet you a man bearing a pitcher of water: follow him. And wheresoever he shall go in, say ye to the goodman of the house, The Master saith, Where is the guestchamber, where I shall eat the Passover with my disciples? And he will shew you a large upper room furnished and prepared: there make ready for us. And his disciples went forth, and came into the city, and found as he had said unto them: and they made ready the Passover.
He sends two of His disciples, that is, Peter and John, as Luke says, to a man unknown to Him, implying by this that He might, if He had pleased, have avoided His Passion. For what could not He work in other men, who influenced the mind of a person unknown to Him, so that he received them? Healso gives them a sign how they were to know the house, when He adds, And there shall meet you a man bearing a pitcher of water.