Exodus 31:16-17

16The Israelites must always keep the Sabbath as a special day. They must obey the rules for the Sabbath day. Those rules are part of my covenant with my people that continues for ever.

17It will always be a sign that I have chosen the Israelites to be my people. You will remember that the Lord made the heavens and the earth in six days. Then, on the seventh day, he stopped working and he rested.” ’