"In this way they waste the whole year with tomfoolery and fiddle-faddle, only in order to avoid doing the king's service. At the expiration of every period of fifty years they have a jubilee year, and every seventh year is a year of release, during which the land lies fallow, for they neither sow nor reap therein, and sell us neither fruits nor other products of the field, so that those of us who live among them die of hunger. At the end of every period of twelve months, they observe the New Year, at the end of every thirty days the New Moon, and every seventh day is the Sabbath, the day on which, as they say, the Lord of the world rested."
A Confused Observer Tries to Explain Jewish Sabbath Customs
Legends of the Jews 12:131