Ezekiel 20:12, 20-21

I also gave them my Sabbaths to be a sign between us so they would know that I am the LORD who made them holy.

Keep my Sabbaths holy, and they will be a sign between me and you. Then you will know that I am the LORD your God.” “ ‘But the children turned against me. They did not live by my rules, nor were they careful to obey my laws, by which people will live if they obey them. They dishonored my Sabbaths. So I decided to pour out my anger against them in the desert.