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.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).