Bible Verses About The Sabbath: A sign of the covenant

Speak thou also unto the children of Israel, saying, Verily ye shall keep my sabbaths: for it is a sign between me and you throughout your generations; that ye may know that I am Jehovah who sanctifieth you.

It is a sign between me and the children of Israel for ever: for in six days Jehovah made heaven and earth, and on the seventh day he rested, and was refreshed.