Ezekiel 20:12, 20-21

Moreover also I gave them my sabbaths, to be a sign between me and them, that they might know that I am Jehovah that sanctifieth them.

and hallow my sabbaths; and they shall be a sign between me and you, that ye may know that I am Jehovah your God. But the children rebelled against me; they walked not in my statutes, neither kept mine ordinances to do them, which if a man do, he shall live in them; they profaned my sabbaths. Then I said I would pour out my wrath upon them, to accomplish my anger against them in the wilderness.