God commanded the Jewish People to observe the Sabbath and keep it holy as the fourth of the Ten Commandments. The idea of a day of rest comes from the Bible story of the Creation: God rested from creating the universe on the seventh day of that first week, so Jews rest from work on the Sabbath.
God created the world in 6 days and on the 7th, he rested. the 7th is the sabbath day when we stop working and praise God for making everything he's done.
