Philo's Account of the Ascetics of Egypt
22 These things the above-mentioned author has related in his own work, indicating a mode of life which has been preserved to the present time by us alone, recording especially the vigils kept in connection with the great festival, and the exercises performed during those vigils, and the hymns customarily recited by us, and describing how, while one sings regularly in time, the others listen in silence, and join in chanting only the close of the hymns; and how, on the days referred to they sleep on the ground on beds of straw, and to use his own words, “taste no wine at all, nor any flesh, but water is their only drink, and the reish with their bread is salt and hyssop.”
23. In addition to this Philo describes the order of dignities which exists among those who carry on the services of the church, mentioning the diaconate, and the office of bishop, which takes the precedence over all the others. But whosoever desires a more accurate knowledge of these matters may get it from the history already cited.
24. But that Philo, when he wrote these things, had in view the first heralds of the Gospel and the customs handed down from the beginning by the apostles, is clear to every one.
Source: Church History (New Advent)