Exodus 31:12-16

12The Lord said to Moses,

13“Tell the Israelites: You must observe my Sabbaths, for it is a sign between me and you throughout your generations, so that you will know that I am the Lord who consecrates you.

14Observe the Sabbath, for it is holy to you. Whoever profanes it must be put to death. If anyone does work on it, that person must be cut off from his people.

15Work may be done for six days, but on the seventh day there must be a Sabbath of complete rest, holy to the Lord. Anyone who does work on the Sabbath day must be put to death.

16The Israelites must observe the Sabbath, celebrating it throughout their generations as a permanent covenant.