Chapter IX.
The reason why a Vigil is appointed as the Sabbath day dawns, and why a dispensation from fasting is enjoyed on the Sabbath all through the East.
And throughout the whole of the East it has been settled, ever since the time of the preaching of the Apostles, when the Christian faith and religion was founded, that these Vigils should be celebrated as the Sabbath dawns, [749] for this reason,--because, when our Lord and Saviour had been crucified on the sixth day of the week, the disciples, overwhelmed by the freshness of His sufferings, remained watching throughout the whole night, giving no rest or sleep to their eyes. Wherefore, since that time, a service of Vigils has been appointed for this night, and is still observed in the same way up to the present day all through the East. And so, after the exertion of the Vigil, a dispensation from fasting, appointed in like manner for the Sabbath by apostolic men, [750] is not without reason enjoined in all the churches of the East, in accordance with that saying of Ecclesiastes, which, although it has another and a mystical sense, is not misapplied to this, by which we are charged to give to both days--that is, to the seventh and eighth equally--the same share of the service, as it says: "Give a portion to these seven and also to these eight." [751] For this dispensation from fasting must not be understood as a participation in the Jewish festival by those above all who are shown to be free from all Jewish superstition, but as contributing to that rest of the wearied body of which we have spoken; which, as it fasts continually for five days in the week all through the year, would easily be worn out and fail, unless it were revived by an interval of at least two days.
[749] The observance of a vigil for the whole or greater part of the night was a regular part of the preparation for the greater festivals, and as such was usual in the East before the Sabbath (Saturday) and Lord's Day, as well as Pentecost and Easter. See Socrates, H. E. VI. viii., where there is an allusion to this.
[750] Saturday, as well as Sunday, was long regarded as a festival in the East, and, indeed, originally in most churches of the West as well. See the Apost. Const. II. lix. 1; VIII. xxxiii. 1. Apost. Canons lxvi.; Council of Laodicæa, Canons xvi., xlix., li.
[751] Eccl. xi. 2.
Chapter X.
How it was brought about that they fast on the Sabbath in the city.
But some people in some countries of the West, and especially in the city, [752] not knowing the reason of this indulgence, think that a dispensation from fasting ought certainly not to be allowed on the Sabbath, because they say that on this day the Apostle Peter fasted before his encounter with Simon. [753] But from this it is quite clear that he did this not in accordance with a canonical rule, but rather through the needs of his impending struggle. Since there, too, for the same purpose, Peter seems to have imposed on his disciples not a general but a special fast, which he certainly would not have done if he had known that it was wont to be observed by canonical rule: just as he would surely have been ready to appoint it even on Sunday, if the occasion of his struggle had fallen upon it: but no canonical rule of fasting would have been made general from this, because it was no general observance that led to it, but a matter of necessity, which forced it to be observed on a single occasion.
[752] Viz., Rome.
[753] The Saturday fast was observed at Rome in very early days, being noticed by Tertullian, who seems to suggest that it originated in the prolongation of the Friday fast (on Fasting, c. xiv). But it seems to have been almost peculiar to Rome, and at Milan, in the time of S. Ambrose, the Eastern custom prevailed. See the important letter of Augustine to Casulanus (Ep. xxxvi.), where the whole subject of the difference of usage on this matter is fully discussed. The reason here given by Cassian for the origin of the local Roman custom (viz., that S. Peter's traditional encounter with Simon Magus took place on Sunday, and was prepared for by the apostle with a Saturday fast) is also there alluded to by Augustine as being the opinion of very many, though he tells us candidly that most of the Romans thought it false. "Est quidem et hæc opinio plurimorum, quamvis eam perhibeant esse falsam plerique Romani, quod Apostolus Petrus cum Simone Mago die dominico certaturo, propter ipsum magnæ tentationis periculum, pridie cum ejusdem urbis ecclesia jejunaverit, et consecuto tam prospero gloriosoque successu, eundem morem tenuerit, eumque imitatæ sunt nonnullæ Occidentis ecclesiæ." Cf. also Augustine, Ep. ad Januarium, liv.