'Sabbath day' in the Bible

Say to the children of Israel that they are to keep my Sabbaths; for the Sabbath day is a sign between me and you through all your generations; so that you may see that I am the Lord who makes you holy.

Six days may work be done, but the seventh day is a Sabbath of complete rest, holy to the Lord; whoever does any work on the Sabbath day is to be put to death.

No fire is to be lighted in any of your houses on the Sabbath day.