Turnus Rufus, the Roman governor of Judea in the early second century, once pulled Rabbi Akiva into a debate on the Shabbat. Rufus opened with the move he thought would win. "I hold my office because the Emperor appointed me. On what authority is your Sabbath appointed?"

"By the King of Kings," Akiva answered.

Rufus smiled. "Then why does your God Himself work on the Sabbath? The wind blows. The rain falls. The sun crosses the sky. Your God breaks His own law."

Akiva was ready. "Within certain limits, the Torah allows a Jew to carry burdens on the Sabbath — within the four cubits of his own private domain, or within a single courtyard shared by all its residents. Our domain is our home. The whole world is God's home. Everything He carries, He carries inside His own courtyard."

Rufus demanded proof that the Sabbath was even a real phenomenon in creation. Akiva gave him two. First, the manna in the wilderness — which fell six days a week but never on the seventh. Second, the legendary river Sanbatyon, which the Rabbis say runs with a furious current six days a week and lies perfectly still on Shabbat. Rufus dismissed both. The manna-eaters were all long dead. The river was in some distant land he had never visited.

"Then ask the necromancers," said Akiva. "They cannot raise the dead on the Sabbath."

The two men summoned a necromancer and called up the spirit of Rufus's own dead father. Nothing came on Saturday. On Sunday, the spirit appeared. "Father," Rufus asked, "have you become a Jew since your death, that you will not answer on the Sabbath?" The spirit answered quietly, "Willing or unwilling, we must keep it. On the Sabbath the punishments in the next world are suspended, and we all rest."

The story, preserved in Moses Gaster's 1924 collection The Exempla of the Rabbis (no. 15), is one of dozens of debates between Akiva and Rufus recorded in rabbinic literature. Its quiet point is enormous. In the world the Rabbis imagined, even the dead keep Shabbat. Even the dead need it. Rest is not a custom. It is a property of the universe, and nothing — not the Roman Empire, not the grave — can unmake it.