Exodus 31:12-17

12And the LORD spoke to Moses, saying, 13Speak thou also to the children of Israel, saying, Verily my sabbaths ye shall keep: for it is a sign between me and you throughout your generations; that ye may know that I am the LORD that doth sanctify you. 14Ye shall keep the sabbath therefore; for it is holy to you: every one that profaneth it shall surely be put to death: for whoever doeth any work in it, that soul shall be cut off from among his people. 15Six days may work be done; but in the seventh is the sabbath of rest, holy to the LORD: whoever doeth any work in the sabbath day, he shall surely be put to death.1 16Therefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant. 17It is a sign between me and the children of Israel for ever: for in six days the LORD made heaven and earth, and on the seventh day he rested, and was refreshed.