Ezekiel 20:20

And hallow my sabbaths
Or keep them holy, by abstaining from worldly business on them; by observing all the duties of religion, private and public, to be performed on such days: and they shall be a sign between me and you;
of present and future good; (See Gill on Ezekiel 20:12); that ye may know that I [am] the Lord your God;
not only acknowledge him to be the Lord their God, by observing his laws, and sanctifying his sabbaths; but also have a larger experience of his grace and goodness, as their covenant God.