"And Moses assembled all of the congregation of the children of Israel and said to them, "These are the things that Adonay has commanded, to do them: Six days work shall be done, and in the seventh day you shall have a holy thing, a Sabbath, a ceasing to Adonay. Anyone who does work in it shall be put to death. You shall not burn a fire in all of your homes on the Sabbath day." (Exodus / Sh'mot 35: 1-3)
The effect of this "turn without signalling" has been to spark the rabbinic imagination. A 2nd century rabbinic text, the Mishnah, connects the two passages and concludes that the "work" that is prohibited in verse 2 is defined by the human activities required to construct and create all of the pieces of the Tabernacle described in the ensuing verses. Thus, building, hammering, planting and sowing, creating fire, cooking, carrying items back and forth, weaving, cutting to measure . . . all of these become prohibited as "work" on Shabbat.
There is another derivation of "work" that is hinted at in verse 2: just as the seventh day was a day of "ceasing" to God--in Genesis/Breishit God rests on the seventh day after creating light and dark, dry land and oceans, plants, animals, stars and moon and humanity--so the seventh day should be a day of "ceasing" from creating for human beings as well.
What is it that we humans create? Our human endeavors, over the ages, have largely been focussed on providing food, clothing and shelter for ourselves and our loved ones. It is certainly the case that today, few of us are directly engaged in wielding a hammer, weeding a vegetable garden or cutting a sewing pattern . . . and when we are, it is more often a hobby or personal passion than a direct, compelling imperative to put clothing on our backs, food on our tables and a secure roof over our heads.
In today's complex economy, we provide food, clothing and shelter for our families by going to work and earning a paycheck and by shopping.
It may be physically challenging to carry a carton of books from the basement to the attic, but it isn't "work" in the Shabbat sense . . . that act of "shlepping" is not contributing to the creation of food, clothing or shelter. It may provide a sense of peace and accomplishment to pull out our knitting on Shabbat afternoon . . . but knitting is a human activity that literally creates clothing and, as such, is an activity proscribed by this definition of Shabbat.
For the majority of us, who have not made the commitment to turn to Jewish law / halachah to guide our actions, why should we turn the week's most convenient errand day into a day that produces no progress in the "food, clothing, shelter" department?
The rabbis of 2000 years ago suggested that Shabbat can be "a taste of the world to come." If we were to project ourselves into an existence where all that toil and worry about food, clothing and shelter were no longer necessary, what would our lives look like? No wallets. No watches. No ATMs. . . . an existence infused with peace and health and security and time to bask in the presence of our loved ones.
That is the potential of a "work-free" Saturday . . . a weekly opportunity to taste the world that might be.