More on the Eighth Day

The Eighth Day, it turns out, comprises an entire division of theological study. Apparently it was appropriated by Christians very early on as a designation of their favoured day of worship. This is what the Epistle of Barnabas has to say:

Chapter 15
8 Finally He saith to them; Your new moons and your Sabbaths I cannot away with. Ye see what is His meaning ; it is not your present Sabbaths that are acceptable [unto Me], but the Sabbath which I have made, in the which, when I have set all things at rest, I will make the beginning of the eighth day which is the beginning of another world.
9 Wherefore also we keep the eighth day for rejoicing, in the which also Jesus rose from the dead, and having been manifested ascended into the heavens.

It is noteworthy, in regards to the previous post, that there is no extant copy of the Septuagint bearing a Psalm dedicated to The Eighth Day. Instead all we are left with are a couple of Psalms (6 and 12) in which the musical notation al-hasheminith is translated as `uper ths ogdonhs. The original Hebrew probably referred to eight strings or perhaps eight notes; this was lost in the translation of "upon the eighth" and apparently was later interpreted as having something to do with the eighth day.

Barnabus wrote in the 2nd century; thus it is very clear that long before Constantines' decree, Christians considered the weekly Lord's Day (to which was eventually tied the annual Pascha, completing the break from the Lunar Sabbath) to have superceded all the feasts of Judaism, right down to the New Moon and Sabbath.

Witness Tertullian, writing Against Marcion at the dawn of the 3rd century:

When, again, he [Paul] mentioned “certain false brethren as having crept in unawares,” who wished to remove the Galatians into another gospel, he himself shows that that adulteration of the gospel was not meant to transfer them to the faith of another god and christ, but rather to perpetuate the teaching of the law; because he blames them for maintaining circumcision, and observing times, and days, and months, and years, according to those Jewish ceremonies which they ought to have known were now abrogated, according to the new dispensation purposed by the Creator Himself, who of old foretold this very thing by His prophets. Thus He says by Isaiah: Old things have passed away. “Behold, I will do a new thing.” And in another passage: “I will make a new covenant, not according to the covenant that I made with their fathers, when I brought them out of the land of Egypt.” In like manner by Jeremiah: Make to yourselves a new covenant, “circumcise yourselves to the Lord, and take away the foreskins of your heart.” It is this circumcision, therefore, and this renewal, which the apostle insisted on, when he forbade those ancient ceremonies concerning which their very founder announced that they were one day to cease; thus by Hosea: “I will also cause all her mirth to cease, her feast-days, her new moons, and her Sabbaths, and all her solemn feasts.” So likewise by Isaiah: “The new moons, and Sabbaths, the calling of assemblies, I cannot away with; your holy days, and fasts, and feast-days, my soul hateth.” Now, if even the Creator had so long before discarded all these things, and the apostle was now proclaiming them to be worthy of renunciation, the very agreement of the apostle’s meaning with the decrees of the Creator proves that none other God was preached by the apostle than He whose purposes he now wished to have recognised, branding as false both apostles and brethren, for the express reason that they were pushing back the gospel of Christ the Creator from the new condition which the Creator had foretold, to the old one which He had discarded.

And, bringing us up to date, here is the Offical Roman Catholic take on the subject, from their Catechism:

2174 Jesus rose from the dead "on the first day of the week." Because it is the "first day," the day of Christ's Resurrection recalls the first creation. Because it is the "eighth day" following the sabbath, it symbolizes the new creation ushered in by Christ's Resurrection. For Christians it has become the first of all days, the first of all feasts, the Lord's Day (he kuriake hemera, dies dominica)--Sunday: We all gather on the day of the sun, for it is the first day (after the Jewish sabbath, but also the first day) when God, separating matter from darkness, made the world; and on this same day Jesus Christ our Savior rose from the dead.