(Exodus 20:9) "Six days you shall labor and do all your work." But is it possible for a person to do all his work in six days? Rather, rest as though all your work were done.
Rest on the Sabbath as Though All Your Work Were Done
Yalkut Shimoni on Torah 296:1
(שמות כ ט) שֵׁשֶׁת יָמִים תַּעֲבֹד וְעָשִׂיתָ כָּל מְלַאכְתֶּךָ, וְכִי אֶפְשָׁר לָאָדָם לַעֲשׂוֹת כָּל מְלַאכְתּוֹ בְּשִׁשָּׁה יָמִים, אֶלָּא שְׁבֹת כְּאִלּוּ מְלַאכְתְּךָ עֲשׂוּיָה.