And I gave them my Sabbaths to be a sign between me and them, that they might know that I am the Lord who sanctify them.
This Sabbath shall appear still more clearly if we count the ages as days, in accordance with the periods of time defined in Scripture, for that period will be found to be the seventh. The first age, as the first day, extends from Adam to the deluge; the second from the deluge to Abraham, equalling the first, not in length of time, but in the number of generations, there being ten in each. From Abraham to the advent of Christ there are, as the evangelist Matthew calculates, three periods, in each of which are fourteen generations—one period from Abraham to David, a second from David to the captivity, a third from the captivity to the birth of Christ in the flesh. There are thus five ages in all. The sixth is now passing, and cannot be measured by any number of generations, as it has been said, “It is not for you to know the times, which the Father has put in His own power.” After this period God shall rest as on the seventh day, when He shall give us (who shall be the seventh day) rest in Himself. But there is not now space to treat of these ages; suffice it to say that the seventh shall be our Sabbath, which shall be brought to a close, not by an evening, but by the Lord’s day, as an eighth and eternal day, consecrated by the resurrection of Christ, and prefiguring the eternal repose not only of the spirit, but also of the body. There we shall rest and see, see and love, love and praise. This is what shall be in the end without end. For what other end do we propose to ourselves than to attain to the kingdom of which there is no end?
Augustine City of God xxii.30