Rebbi Akiva's answer to Turnusrupus Harasha (the Evil One) who asked why doesn't G-d keep Shabbos. The whole world belongs to Hashem. Shabbos is an opportunity to leave the falsehood of the reshus ha'rabim (public throughfare), to re-focus our attention on spiritual matters, by reminding ourselves that this is all the private domain of God. It is only through this perspective that we can begin to try to work on menuchas hanafesh.