It was the last important truth and commandment urged from Mount Sinai, when God… Exodus 31:18 ...made an end of communing with Moses upon the Mount.
It was then and there urged and enjoined by the most powerful motives. 12 And the Lord spoke unto Moses, saying, 13 Speak also unto the children of Israel, saying, Verily 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 that does sanctify you. 14 You shall keep the sabbath therefore; for it is holy unto you: every one that defiles it shall surely be put to death: for whosoever does any work therein, that soul shall be cut off from among his people. 15 Six days may work be done; but in the seventh is the sabbath of rest, holy to the Lord...."
James White