Of the Shabbath he spoke in the beginning of the creation. And
God made the works of his hands in 6 days, and he ended on the
7th day, and rested on it, and he set it apart. Give heed, children, what this means; He ended in 6 days. He means this, that in 6,000 years the Master shall bring all things to an end, for 1 day with him signifies a 1,000 years. And with this he himself bears me witness, saying, “behold, the day of the Master shall be as a 1,000 years”. Therefore, children, in 6 days, that is in 6,000 years, everything shall come to an end. And he rested on the 7th day. By this he means, when his son shall come, and shall abolish the time of the torahless one, and shall judge the impious, then shall he truly rest on the 7th day.
Barnabas 15:4-5