The Torah says, "Six days shall you do your work" (Exodus 23:12), a commandment to labor for six days and rest on the seventh, the Shabbat (the Sabbath). But the Mekhilta noticed something unusual about the placement of this verse. It appears in close proximity to the laws of shevi'ith, the sabbatical year, when the land itself must rest and all agricultural work ceases for an entire year.
This juxtaposition raised a question: during the sabbatical year, when a person is already forbidden from working the land, does the weekly Sabbath still apply? One might argue that if you are already resting from agricultural labor for the entire year, the weekly rest becomes redundant. The Mekhilta answers decisively: the Sabbath of creation is not superseded by the sabbatical year. Both obligations remain in force simultaneously.
The reasoning reveals a deep principle about the nature of Shabbat. The weekly Sabbath is not merely a labor regulation. It is a commemoration of God's creation of the world, a cosmic rhythm built into the fabric of time itself. The sabbatical year, by contrast, is an agricultural law tied to the land of Israel. The two rest periods serve different purposes, and fulfilling one does not exempt you from the other. Even during a year when the fields lie fallow and the farmer has nothing to do, the seventh day retains its sanctity. Shabbat exists not because humans need rest, but because God rested, and no earthly calendar, not even the Torah's own sabbatical cycle, can overrule that primordial pattern.