The Epistle of Barnabas
Chapter 15: The False and the True Sabbath
Furthermore, it is written about the Sabbath in the Decalogue, which the Lord spoke directly to Moses on Mount Sinai, “And sanctify the Sabbath of the Lord with clean hands and a pure heart.” And He says in another place, “If my children keep the Sabbath, then I will let my mercy rest upon them.” The Sabbath is mentioned at the beginning of creation like this: “And God made in six days the works of His hands, and finished on the seventh day, and rested on it, and sanctified it.” Pay attention, my children, to the meaning of the phrase, “He finished in six days.” This implies that the Lord will complete all things in six thousand years, for with Him a day is like a thousand years.
And He Himself confirms this by saying, “Behold, today will be as a thousand years.” Therefore, my children, in six days, meaning in six thousand years, all things will be completed. “And He rested on the seventh day.” This means that when His Son returns, He will destroy the time of the wicked, judge the ungodly, and change the sun, moon, and stars, then He will truly rest on the seventh day.
Moreover, He says, “You shall sanctify it with pure hands and a pure heart.” If, therefore, anyone can now sanctify the day which God has sanctified, unless they are pure in heart in all things, we are mistaken.
Behold, therefore: certainly one properly resting sanctifies it when we ourselves, having received the promise, and with wickedness no longer existing, and all things having been renewed by the Lord, are able to practice righteousness. Then we will be able to sanctify it, having first been sanctified ourselves.
Furthermore, He says to them, “Your new moons and your Sabbaths I cannot endure.” You see how He speaks: Your current Sabbaths are not acceptable to Me, but that which I have made, namely this: when I give rest to all things, I will begin the eighth day, that is, the start of another world.
Therefore, we also keep the eighth day with joyfulness, the day on which Jesus rose again from the dead. And when He had revealed Himself, He ascended into the heavens.