Numbers 14:11 Then the LORD said to Moses: “How long will these people reject Me? And how long will they not believe Me, with all the signs which I have performed among them?
Deuteronomy 11:18 “Therefore you shall lay up these words of mine in your heart and in your soul, and bind them as a sign on your hand, and they shall be as frontlets between your eyes.
Exodus 31:13 "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 you.
Ezekiel 20:12 Moreover I also gave them My Sabbaths, to be a sign between them and Me, that they might know that I am the LORD who sanctifies them.