Exodus 16:29

16:29 See, because the Lord has given you the Sabbath, that is why he is giving you food for two days on the sixth day. Each of you stay where you are; let no one go out of his place on the seventh day.”

Exodus 20:11

20:11 For in six days the Lord made the heavens and the earth and the sea and all that is in them, and he rested on the seventh day; therefore the Lord blessed the Sabbath day and set it apart as holy.

Exodus 31:14

31:14 So you must keep the Sabbath, for it is holy for you. Everyone who defiles it must surely be put to death; indeed, if anyone does any work on it, then that person will be cut off from among his people.