Exodus 35:1-3

Then Moses assembled all the congregation of the sons of Israel, and said to them, “These are the things that the LORD has commanded you to do: “For six days work may be done, but on the seventh day you shall have a holy day, a sabbath of complete rest to the LORD; whoever does any work on it shall be put to death. You shall not kindle a fire in any of your dwellings on the sabbath day.”