12 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?
[AD 220] Tertullian on Mark 14:12
The Passover affords a more than usually solemn day for baptism; when, withal, the Lord's passion, in which we are baptized, was completed. Nor will it be incongruous to interpret figuratively the fact that, when the Lord was about to celebrate the last Passover, He said to the disciples who were sent to make preparation, "You will meet a man bearing water." He points out the place for celebrating the Passover by the sign of water. After that, Pentecost is a most joyous space for conferring baptisms; wherein, too, the resurrection of the Lord was repeatedly proved among the disciples [Acts 1:3], and the hope of the advent of the Lord indirectly pointed to, in that, at that time, when He had been received back into the heavens [Acts 1:9], the angels told the apostles that "He would so come, as He had withal ascended into the heavens;" [Acts 1:11] at Pentecost, of course. But, moreover, when Jeremiah says, "And I will gather them together from the extremities of the land in the feast-day," he signifies the day of the Passover and of Pentecost, which is properly a "feast-day." However, every day is the Lord's; every hour, every time, is apt for baptism: if there is a difference in the solemnity, distinction there is none in the grace.

[AD 220] Tertullian on Mark 14:12
And the suffering of this "extermination" was perfected within the times of the lxx hebdomads, under Tiberius Caesar, in the consulate of Rubellius Geminus and Fufius Geminus, in the month of March, at the times of the passover, on the eighth day before the calends of April, on the first day of unleavened bread, on which they slew the lamb at even, just as had been enjoined by Moses. Accordingly, all the synagogue of Israel did slay Him, saying to Pilate, when he was desirous to dismiss Him, "His blood be upon us, and upon our children; " and, "If thou dismiss him, thou art not a friend of Caesar; " in order that all things might be fulfilled which had been written of Him.

[AD 220] Tertullian on Mark 14:12
For that you would do thus at the beginning of the first month of your new (years) even Moses prophesied, when he was foretelling that all the community of the sons of lsrµl was to immolate at eventide a lamb, and were to eat this solemn sacrifice of this day (that is, of the passover of unleavened bread) with bitterness; "and added that "it was the passover of the Lord," that is, the passion of Christ. Which prediction was thus also fulfilled, that "on the first day of unleavened bread" you slew Christ; and (that the prophecies might be fulfilled) the day hasted to make an "eventide,"-that is, to cause darkness, which was made at mid-day; and thus "your festive days God converted into grief, and your canticles into lamentation.

[AD 407] John Chrysostom on Mark 14:12-16
(ubi sup.) Whilst Judas was plotting how to betray Him, the rest of the disciples were taking care of the preparation of the Passover: wherefore it is said, 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 where thou mayest eat the Passover.

(ubi sup.) Not our Passover, but in the meanwhile that of the Jews; but He did not only appoint ours, but Himself became our Passover. Why too did He eat it? Because He was made under the Law, to redeem them that were under the Law, (Gal. 4:4) and Himself give rest to the Law. And lest any one should say that He did away with it, because He could not fulfil its hard and difficult obedience, He first Himself fulfilled it, and then set it to rest.

[AD 430] Augustine of Hippo on Mark 14:12-16
(de Con. Evan. ii. 80) Mark says a pitcher, Luke a two-handled vessel; one points out the kind of vessel, the other the mode of carrying it; both however mean the same truth.

[AD 735] Bede on Mark 14:12-16
(ubi sup.) He means by the first day of the Passover the fourteenth day of the first month, when they threw aside leaven, and were wont to sacrifice, that is, to kill the lamb at even. The Apostle explaining this says, Christ our Passover is sacrificed for us. (1 Cor. 5:7) For although He was crucified on the next day, that is, on the fifteenth moon, yet on the night when the lamb was offered up, He committed to His disciples the mysteries of His Body and Blood, which they were to celebrate, and was seized upon and bound by the Jews; thus He consecrated the beginning of His sacrifice, that is, of His Passion.

(ubi sup.) And it is a proof of the presence of His divinity, that in speaking with His disciples, He knows what is to take place elsewhere; wherefore it follows, And his disciples went forth, and came into the city, and found as he had said unto them; and they made ready the Passover.

(ubi sup.) Or else, the water is the laver of grace, the pitcher points out the weakness of those who were to show that grace to the world.

(ubi sup.) Or else, the large upper-room is spiritually the Law, which comes forth from the narrowness of the letter, and in a lofty place, that is, in the lofty chamber of the soul, receives the Saviour. But it is designedly that the names both of the bearer of the water, and of the lord of the house, are omitted, to imply that power is given to all who wish to celebrate the true Passover, that is, to be embued with the sacraments of Christ, and to receive Him in the dwelling-place of their mind.

[AD 735] Bede on Mark 14:12
On the first day of unleavened bread, when they sacrificed the Passover, the disciples said to Him: Where do You want us to go and prepare for You to eat the Passover? He calls the first day of unleavened bread the fourteenth day of the first month when, having cast away the leaven, they used to sacrifice the Passover, that is, kill the lamb in the evening. Explaining this, the Apostle says: For even Christ our Passover has been sacrificed (I Cor. V). Although He was crucified on the following day, that is on the fifteenth moon, yet on this night when the lamb was sacrificed, He handed over to His disciples the mysteries of His body and blood to be celebrated, and being captured and bound by the Jews, He hallowed the beginning of His own sacrificing, that is, of His passion.

[AD 1107] Theophylact of Ohrid on Mark 14:12-16
From the words of the disciples, Where wilt thou that we go? it seems evident that Christ had no dwelling-place, and that the disciples had no houses of their own; for if so, they would have taken Him thither.

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? He also 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.

He who is baptized carries the pitcher of water, and he who bears baptism upon him comes to his rest, if he lives according to his reason; and he obtains rest, as being in the house. Wherefore it is added, Follow him.

Or else, the lord of the house is the intellect, which points out the large upper room, that is, the loftiness of intelligences, and which, though it be high, yet has nothing of vain glory, or of pride, but is prepared and made level by humility. But there, that is, in such a mind Christ's Passover is prepared by Peter and John, that is by action and contemplation.

[AD 1274] Pseudo-Jerome on Mark 14:12-16
But the unleavened bread which was eaten with bitterness, that is with bitter herbs, is our redemption, and the bitterness is the Passion of our Lord.

For they say, Where wilt thou that we go? to show us that we should direct our steps according to the will of God. But the Lord points out with whom He would eat the Passover, and after His custom He sends two disciples, which we have explained above; wherefore it goes on, And he sendelh forth two of his disciples, and he saith unto them, Go ye into the city.

And in a mystical sense the city is the Church, surrounded by the wall of faith, the man who meets them is the primitive people, the pitcher of water is the law of the letter.

That is, him who leads to the lofty place, where is the refreshment prepared by Christ. (John 21:15) The lord of the house is the Apostle Peter, to whom the Lord has entrusted His house, that there may be one faith under one Shepherd. The large upper-room is the wide-spread Church, in which the name of the Lord is spoken of, prepared by a variety of powers and tongues.