In this view, the Sabbath is a “social institution equalizing all creatures”11 or a “period of taboo.”12 It was an economic and social institution similar to the Roman market-day (nundinae).13 The Sabbath, then, would have derived from an “almost universal custom of keeping days of rest, or feast days, or market days, at regular intervals.”14 Two conflicting theories are proposed with great erudition: There is the fifty-day scheme that is based on the seven winds