Exodus 31:12-13 New King James Version (NKJV)
The Sabbath Law
12 And the Lord spoke to Moses, saying, 13 “Speak also to the children of Israel, saying: ‘Surely My Sabbaths you shall keep, for it is a sign between Me and you throughout your generations, that you may know that I am the Lord who sanctifies[a] you.
Exodus 31:12-13 New International Version (NIV)
12 Then the Lord said to Moses, 13 “Say to the Israelites, ‘You must observe my Sabbaths. This will be a sign between me and you for the generations to come, so you may know that I am the Lord, who makes you holy.