Eusebius of Caesarea
Catena Aurea · Lukasevangelium 22
Then came the day of unleavened bread, when the Passover must be killed. And he sent Peter and John, saying, Go and prepare us the Passover, that we may eat. And they said unto him, Where wilt thou that we prepare? And he said unto them, Behold, when ye are entered into the city, there shall a man meet you, bearing a pitcher of water; follow him into the house where he entereth in. And ye shall say unto the goodman of the house, The Master saith unto thee, Where is the guestchamber, where I shall eat the Passover with my disciples? And he shall shew you a large upper room furnished: there make ready. And they went, and found as he had said unto them: and they made ready the Passover.
But should any one say, “If on the first day of unleavened bread the disciples of our Saviour prepare the Passover, on that day then should we also celebrate the Passover;” we answer, that this was not an admonition, but a history of the fact. It is what took place at the time of the saving Passion; but it is one thing to relate past events, another to sanction and leave them an ordinance to posterity. Moreover, the Saviour did not keep His Passover with the Jews at the time that they sacrificed the lamb. For they did this on the Preparation, when our Lord suffered. Therefore they entered not into the hall of Pilate, that they might not be defiled, but might eat the Passover. (John 18:28.) For from the time that they conspired against the truth, they drove far from them the Word of truth. Nor on the first day of unleavened bread, on which the Passover ought to be sacrificed, did they eat their accustomed Passover, for they were intent upon something else, but on the day after, which was the second of unleavened bread. But our Lord on the first day of unleavened bread, that is, on the fifth day of the week, kept the Passover with His disciples.