HKB
of the same month is the feast of unleavened bread unto the Lord; seven days ye must eat unleavened bread. In the first day ye shall have an holy convocation.’
“If therefore it could be that the Lord’s day should always happen on the fifteenth day of the first month, that is, on the fifteenth moon, we might always celebrate the Passover at one and the same time with the ancient people of God, though the nature of the mystery be different, as we do it with one and the same faith. But inasmuch as the day of the week does not keep pace exactly with the moon, the Apostolic tradition, which was preached at Rome by the blessed Peter, and confirmed at Alexandria by Mark the Evangelist,(963) his interpreter, appointed that when the first month was come, and in it the evening of the fourteenth day, we should also wait for the Lord’s day, between the fifteenth and the one-and-twentieth day of the same month. For on whichever of those days it shall fall, Easter will be rightly kept on the same; seeing that it is one of those seven days on which the feast of unleavened bread is commanded to be kept. Thus it comes to pass that our Easter never falls either before or after the third week of the first month, but has for its observance either the whole of it, to wit, the seven days of unleavened bread appointed by the law, or at least some of them. For though it comprises but one of them, that is, the seventh, which the Scripture so highly commends, saying,(964) ‘But the seventh day shall be a more holy convocation, ye shall do no servile work therein,’ none can lay it to our charge, that we do not rightly keep Easter Sunday, which we received from the Gospel, in the third week of the first month, as the Law prescribes.
“The catholic reason of this observance being thus explained, the unreasonable error, on the other hand, of those who, without any necessity, presume either to anticipate, or to go beyond the term appointed in the Law, is manifest. For they that think Easter Sunday is to be observed from the fourteenth day of the first month till the twentieth moon, anticipate the time prescribed in the law, without any necessary reason; for when they begin to celebrate the vigil of the holy night from the evening of the thirteenth day, it is plain that they make that day the beginning of their Easter, whereof they find no mention in the commandment of the Law; and when they avoid celebrating our Lord’s Easter on the one-and-twentieth day of the month, it is surely manifest that they wholly exclude that day from their solemnity, which the Law many times commends to be observed as a greater festival than the rest; and thus, perverting the proper order, they sometimes keep Easter Day entirely in the second week, and never place it on the seventh day of the third week. And again, they who think that Easter is to be kept from the sixteenth day of the said month till the two-and-twentieth(965) no less erroneously, though on the other side, deviate from the right way of truth, and as it were avoiding shipwreck on Scylla, they fall into the whirlpool of Charybdis to be drowned. For when they teach that Easter is to be begun at the rising of the sixteenth moon of the first month, that is, from the evening of the fifteenth day, it is certain that they altogether exclude from their solemnity the fourteenth day of the same month, which the Law first and chiefly commends; so that they scarce touch the evening of the fifteenth day, on which the people of God were redeemed from Egyptian bondage, and on which our Lord, by His Blood, rescued the world from the darkness of sin, and on which being also buried, He gave us the hope of a blessed rest after death.