Rabbi Eliezer and Rabbi Yehoshua were sailing across the Mediterranean when a terrible storm seized their ship. Winds howled, waves crashed over the deck, and the vessel was driven far off course into the open ocean — waters no Jewish sage had ever navigated.
Rather than despair, Rabbi Eliezer said to his companion: "We must have been driven here for a reason. God does not send His servants into the deep without purpose." So they took a cask and filled it with ocean water — a sample of the mysterious sea that had swallowed them.
When they eventually reached Rome — carried there by the same storm or by subsequent travels — the Emperor Hadrian challenged them with a question about the nature of the ocean. "Your Torah speaks of the waters of the deep. Tell me: why does the ocean never overflow? Rivers pour into it endlessly, rain falls upon it without ceasing, yet it never rises above its banks."
Rabbi Eliezer produced the cask of ocean water. "Watch," he said. He began pouring water into the cask — fresh water, river water, any water at hand. He poured and poured. The cask never overflowed. The ocean water within it absorbed everything that was added, as though the cask were bottomless.
The Emperor watched in amazement. The sages had brought proof from the ocean itself: its waters are ever-swallowing, ever-absorbing, a vessel that drinks without limit. Just as the ocean can hold infinite water, the sages implied, so can the Torah hold infinite wisdom — and so can the human mind, if it opens itself to learning without setting boundaries on what it can contain.