Imagine for a moment, that Jerome, or Musaeus, or Alcuin, or Bede formed such a collection of lessons, covering not only the Sundays of the year, but the feria, and festivals and martyrdays, when nothing of the kind had fixed itself in the general habit of the Church before! Who cannot see at once how impossible it would be to introduce such a collection from diocese to diocese throughout the Church, when Catholic tradition and custom had all the authority of common law, and to accomplish this too without one syllable of earnest protest, or without any intimation of resistance? It is absurd. These Lectionaria could not, of themselves, have introduced the practice as something before unknown, but rather the general custom already existing necessitated their formation to serve its own ends. The Lectionaria themselves, as we shall see, give clear evidence of this.
Augusti, in his valuable work on Christian antiquities (vol. vi. p. 211), has given a carefully prepared synopsis of part of the four works just mentioned above. From an examination of this synopsis, the close uniformity of the pericopes and other Scripture readings connected with the ancient and leading festivals of the Church, is plainly observable. Take for example the Epiphany festival, undoubtedly of extreme antiquity, which, while referring back to the Nativity and Circumcision of Christ, included the adoration of the Wise men led by the miraculous star, the baptism at Jordan, and the first miracle at Cana. Here the uniformity is complete in all the general features. The pericopes for Circumcision are in the Menologium, Luke ii. 21-40; in the Liber Comitis, Luke ii. 21-32; in the Lectionarium Gall., Luke ii. 21-40, including an Epistle, 1 Cor. x. 14-31; in the Callendarium Rom., Luke ii. 21-32. For Epiphany, in the Menolog., Matt. iii. 13-17 (the Baptism); in the Lib. Com. Matt. ii. 1-12 (the adoration of the Wise men, with an octave, however, taking up the Baptism); in the Lect. Gall., Matt. iii. 13-17, combined with John ii. (the first miracle); in the Callend. Rom., Matt. ii. 1-12.
It is plain that the uniformity here manifest has its ground in the early and wide spread custom of the Church, and not in any individual and arbitrary compilation imposed by this one or that one—a custom too contemporaneous, we may say, with the observance of the festival itself, which grouped around it a cluster of pericopes of uniform character, as seen above. This is further and more fully confirmed the moment we examine the homilies of the early Fathers.
Among the sermons ascribed to St. Ambrose, there is one which shows at once how it came that the singular epistle selection, 1 Cor. x. 14-31, found its way into the Lectionarium Gall. for Circumcision. This selection, as may be seen by examination, brings into view the striking contrast between the Gentile sacrificial and idolatrous festivity, and the Christian's communion through the Eucharist, with the sacrifice of Christ. There seems to be here no connection whatever between the Circumcision of Christ, and this exhortation of St. Paul; and what custom of the Church could have made such a selection of any general force in reference to the day? Just this. Around the opening of January there was quite a cluster of Gentile feasts. Among the Romans were the celebrated Saturnalia, covering some seven days, followed by the Laurentalia, and then again after the Calends, the Agonalia. On the Calends itself there was a wild riotous festival in honor of Janus, and Strenia, the goddess of presents, and the day was given up to feastings and banquetings, and revelry. Christians were guarded against all this by very severe canons of several councils, and by the earnest watchfulness of their Pastors. In the sermon referred to, as also in one for the same season from Augustine, the hearers are at once reminded of the necessary contrast between their festivity and that of the Gentiles, and are told that those who wish to be partakers of the Divine, should hold no fellowship with idols, for the portion of idols is drunkenness, gluttony and dance. Augustine, indeed, in bringing out the same contrast, refers to this very chapter in Corinthians. There can be but little doubt that just this need of enforcing such contrast in view of the surrounding heathenism originated, long before Ambrose, the use of such a lesson as this as well as that one of kindred character in the same Lectionarium for Epiphany, viz., Titus i. 11 to the end.