“Moses, you spoke well!”
At first glance, Rav Safra’s enthusiastic response to Rava’s teaching appears to be the highest of praise. What could be more complementary than comparing a colleague to Moses, the man who led Israel out of Egypt, who spoke to God face-to-face, and whom the rabbis frequently refer to as Moshe Rabbenu — “Moses our rabbi”?
Or, perhaps not. On today’s daf, the rabbis of the Gemara are discussing a mishnah from the previous page which, once again, concerns transferring objects between domains on Shabbat:
If boats are tied together, one may carry an object from one to the other on Shabbat. If they are not tied, even though they are adjacent, one may not carry from one to the other.
The Gemara raises an objection: this teaching is obvious! This is actually a common sort of objection raised by the Gemara. It arises from a rabbinic assumption that every part of the Mishnah is important and relevant — no teaching is superfluous. When the Gemara objects that a mishnaic statement appears to be obvious, this requires a response that reveals how, in fact, that particular mishnah teaches something novel.
At first, it is Rava who comes in to rescue this “obvious” mishnah:
Rava said: This mishnah was necessary to permit carrying from one boat to another via a small boat that is between them.
In Rava’s view, while it is obvious that one can carry directly between two boats that are tied together on Shabbat, the mishnah teaches that one is also permitted to use a small shuttle boat to transfer objects between them.
This is when Rav Safra exclaims: Moses, you spoke well!
But then Rav Safra undoes Rava’s teaching, showing how language in the mishnah — specifically the use of the words mi zo le zo (מזו לזו), which implies a direct transfer — rules out the use of shuttle boats.
Now we are back to the original problem: the mishnah seems superfluous. What is it actually teaching us? Rav Safra has an answer for that too: the mishnah is necessary to teach us that when two boats that are tied together are owned by two different people, an eruv (a joining of private spaces) is required to enable carrying between them on Shabbat. This is the real novel teaching of this mishnah.
Rashi suggests that we read Rav Safra’s response to his colleague’s weak solution — Moses, you spoke well! — with astonishment. Rav Safra is flabbergasted that Rava would offer an explanation so easily knocked down.
Or perhaps we have come across a moment of nearly 2000-year-old rabbinic sarcasm, an ancient equivalent of the modern-day, “Way to go, Einstein!” I imagine Rav Safra smiling as he said it, offering not a harsh rebuke but a loving jab. It brought a smile to my face as well.