"And the reason why they were to keep the Sabbath was because the Creator rested on the seventh day—not period. If you say six periods, instead of six days, what becomes of your Sabbath? The only reason given in the Bible for observing the Sabbath is that God observed it—that he rested from his work that day and was refreshed. Take this reason away and the sacredness of that day has no foundation in the Scriptures."
January 1, 1970
https://en.wikiquote.org/wiki/Robert_G._Ingersoll