Another matter, “all the rivers go to the sea,” this is the ocean, “yet the sea is not full,” this is the ocean that is never full. There was an incident involving Rabbi Eliezer and Rabbi Yehoshua who were sailing in the Mediterranean Sea. The ship entered a place where the water does not flow. Rabbi Eliezer said to Rabbi Yehoshua: We came here only for the purposes of an ordeal.
They filled a barrel full with water. When they arrived in Rome, Hadrian said to them: ‘What is the nature of ocean water?’ They said to him: ‘It is water that swallows water,’ and he said to them: ‘Is it possible that all the rivers flow there and they do not fill?’ They said to him: ‘They swallow all the water in the world.’
He said to them: ‘I do not believe you until you show it to me here.’ They took the water that they had drawn from the ocean and filled a bowl with water. They poured [more] water into it and [the ocean water] swallowed [it and did not overflow]. In the opinion of Rabbi Eliezer, from there they draw.43In his opinion, the clouds absorb rain water from the ocean, after which it rains into the rivers, and the rivers then flow back into the ocean.
That is what is written: “To the place that the rivers go, they go there again.” In the opinion of Rabbi Yehoshua: “They go there again.”44The rivers continually flow into the ocean, where they are swallowed by the ocean water.