Exodus 31:14 in the King James Version
Ye shall keep the sabbath therefore; for it is holy unto you: every one that defileth it shall surely be put to death: for whosoever doeth any work therein, that soul shall be cut off from among his people.
Context
13 “Speak also to the children of Israel, saying, ‘Most certainly you shall keep my Sabbaths; for it is a sign between me and you throughout your generations, that you may know that I am the LORD who sanctifies you.
14 You shall keep the Sabbath therefore, for it is holy to you. Everyone who profanes it shall surely be put to death; for whoever does any work therein, that soul shall be cut off from among his people.
15 Six days shall work be done, but on the seventh day is a Sabbath of solemn rest, holy to the LORD. Whoever does any work on the Sabbath day shall surely be put to death.