Exodus 31:12-14

The LORD spoke to Moses, saying, “But as for you, speak to the sons of Israel, saying, ‘You shall surely observe My sabbaths; for this is a sign between Me and you throughout your generations, that you may know that I am the LORD who sanctifies you. Therefore you are to observe the sabbath, for it is holy to you. Everyone who profanes it shall surely be put to death; for whoever does any work on it, that person shall be cut off from among his people.