1 After two days was the feast of the passover, and of unleavened bread: and the chief priests and the scribes sought how they might take him by craft, and put him to death.
[AD 735] Bede on Mark 14:1-2
(in Marc. iv. 43) Pascha which in Hebrew is phase, is not called from Passion, as many think, but from passing over, because the destroyer, seeing the blood on the doors of the Israelites, passed by them, and did not smite them; or the Lord Himself, bringing aid unto His people, walked above them.

(ubi sup.) The difference according to the Old Testament between the Passover and the feast of unleavened bread was, that the day alone on which the lamb was slain in the evening, that is, the fourteenth moon of the first month, was called Passover. But on the fifteenth moon, when they came out of Egypt, the feast of unleavened bread came on, which solemn time was appointed for seven days, that is, up to the twenty-first day of the same month in the evening. But the Evangelists indifferently use the day of unleavened bread for the Passover, and the Passover for the days of unleavened bread. Wherefore Mark also here says, After two days was the feast of the Passover, and of unleavened bread, because the day of the Passover was also ordered to be celebrated on the days of unleavened bread, and we also, as it were, keeping a continual passover, ought always to be passing out of this world.

(ubi sup.) Not indeed, as the words seem to imply, that they feared the uproar, but they were afraid lest He should be taken out of their hands by the aid of the people.

[AD 735] Bede on Mark 14:1
Now it was the Passover, and the unleavened bread after two days. Passover, which is called "phase" in Hebrew, is named not from suffering as many think, but from passing over, because the destroyer, seeing the blood on the doorposts of the Israelites, passed over and did not strike them, or the Lord Himself providing aid to His people passed over them. Explaining the sacrament of this word more sublimely, the evangelist John says: "Before the feast of the Passover, Jesus knowing that his hour had come that he should pass out of this world unto the Father" (John XIII). Where he clearly declares that the day of this solemnity is mystically called the Passover through the law because the Lamb of God who takes away the sins of the world, in it, would either pass from this world, or lead us out of the servitude of Egypt through a wholesome passage. Certainly, according to the scripture of the Old Testament, there is a distinction between Passover and unleavened bread, in that Passover itself is called the single day on which the lamb was killed in the evening, that is, the fourteenth moon of the first month. The fifteenth moon, however, when they left Egypt, followed the festival of unleavened bread, which for seven days, that is, until the twenty-first day of the same month in the evening, the solemnity was established. Indeed, the evangelists interchangeably use the day of unleavened bread for Passover and Passover for the days of unleavened bread. For Mark says: “Now the Passover and the unleavened bread were after two days” (Mark XIV). Luke says: “The festival day of the unleavened bread, which is called Passover” (Luke XXII). Also, John, when on the first day of the unleavened bread, that is, the fifteenth moon, the act was being carried out, says: "And they did not enter into the Praetorium, that they might not be defiled, but might eat the Passover" (John XVIII). They did this because the day of Passover is also commanded to be celebrated with unleavened bread, and we, as if making a perpetual Passover, are always commanded to pass from this world. For on the one day the lamb was sacrificed in the evening, and seven days of unleavened bread successively followed, because Christ Jesus, having once suffered for us in the fullness of time in the flesh, commanded that through the whole time of this age (which is conducted in seven days), we must live in the unleavened bread of sincerity and truth (I Cor. V), and always by every effort, we are admonished to flee earthly desires as the bindings of Egypt, and to undertake a secret solitude of virtues as if from worldly conversation.

[AD 735] Bede on Mark 14:1
And the chief priests and scribes sought how they might take Him by craft and kill Him. But they said, Not on the feast day, lest there be an uproar among the people. Those who ought to have been preparing the sacrifices for the nearby Passover, cleaning the temple walls, sweeping the floors, cleansing the vessels, and purifying themselves according to the law so that they would be worthy to eat the lamb, gathered together, taking counsel on how to kill the Lord, not fearing a sedition, as the simple phrase shows, but avoiding that He be taken from their hands by the help of the people.

[AD 1107] Theophylact of Ohrid on Mark 14:1-2
Nevertheless, Christ Himself had determined for Himself the day of His Passion; for He wished to be crucified on the Passover, because He was the true Passover.

[AD 1274] Pseudo-Jerome on Mark 14:1-2
Let us now sprinkle our book, and our thresholds with blood, and put the scarlet thread around the house of our prayers, and bind scarlet on our hand, as was done to Zarah, (Gen. 38:30) that we may be able to say that the red heifer is slain in the valley. (Num. 19:2, Deut. 21:4) For the Evangelist, being about to speak of the slaying of Christ, premises, After two days was the feast of the Passover, and of unleavened bread.

Or else phase is interpreted a passing over, but Pascha means sacrifice. In the sacrifice of the lamb, and the passing of the people through the sea, or through Egypt, the Passion of Christ is prefigured, and the redemption of the people from hell, when He visits us after two days, that is, when the moon is most full, and the age of Christ is perfect, that when no part at all of it is dark, we may eat the flesh of the Lamb without spot, who taketh away the sins of the world, in one house, that is, in the Catholic Church, shod with charity, and armed with virtue.

But iniquity came forth in Babylon from the princes, who ought to have purified the temple and the vessels, and themselves according to the law, in order to eat the lamb. Wherefore there follows: And the Chief Priests and the Scribes sought how they might take him by craft, and put him to death. Now when the head is slain, the whole body is rendered powerless, wherefore these wretched men slay the Head. But they avoid the feast day, which indeed befits them, for what feasting can there be for them, who have lost life and mercy? Wherefore it goes on: But they said, Not on the feast day, lest there be an uproar of the people.