Six days you shall labour and do all your work, but the seventh day is a sabbath to the Lord your God. On it you shall not do any work, neither you, nor your son or daughter, nor your male or female servant… Remember that you were slaves in Egypt and that the Lord your God brought you out of there… Therefore the Lord your God has commanded you to observe the Sabbath day. 

Deuteronomy 5: 11-14