How among the Egyptians they apply themselves all day long to prayer and Psalm continually, with the addition of work, without distinction of hours.
For among them (viz., the Egyptians) these offices which we are taught to render to the Lord at separate hours and at intervals of time, with a reminder from the convener, are celebrated continuously throughout the whole p. 213 day, with the addition of work, and that of their own free will. For manual labour is incessantly practised by them in their cells in such a way that meditation on the Psalms and the rest of the Scriptures is never entirely omitted. And as with it at every moment they mingle suffrages and prayers, they spend the whole day in those offices which we celebrate at fixed times. Wherefore, except Vespers and Nocturns, there are no public services among them in the day except on Saturday and Sunday, when they meet together at the third hour for the purpose of Holy Communion. 717 For that which is continuously offered is more than what is rendered at intervals of time; and more acceptable as a free gift than the duties which are performed by the compulsion of a rule: as David for this rejoices somewhat exultingly when he says, “Freely will I sacrifice unto Thee;” and, “Let the free will offerings of my mouth be pleasing to Thee, O Lord.” 718
The Saturday Communion (in addition to that of Wednesday and Friday, as well as Sunday) is also mentioned by S. Basil (Ep. xciii.), and cf. the Forty-ninth Canon of the Council of Laodicæa (circa 360 a.d.): “During Lent the bread shall not be offered except on Saturday and Sunday.” In the West there is no trace of a special Saturday celebration of the Holy Communion.
The third hour was the ordinary time for Holy Communion, as may be seen from the decree (falsely) ascribed to Pope Telesphorus (a.d. 127–138), in the Liber Pontificalis: “Ut nullus ante horam tertiam sacrificium offere præsumeret,” and many other testimonies.213:718
Ps. 54:8, Ps. 119:108.