What does it mean when you read a certain Rabbi said in the name of another Rabbi?

Question

I'm a Roman Catholic wading through the Midrash of Tehillim. What does it mean when you read a certain Rabbi said in the name of another Rabbi?

Answer 1

Welcome. In Rabbinic literature (as in many other places) it's important to give sources. Passing off someone else's ideas as your own is unethical. Giving your source also allows the listener to evaluate how much weight or credibility the statement should be given, and can give more stature to the speaker's words. That's why so many quotations are often misattributed to influential figures like Einstein, Gandhi, etc. This was especially important because much of the early literature (such as the Mishnah, Talmud, and many midrashim) were originally orally transmitted, so there was no other place to look these statements up. For all these reasons, Rabbi Elazar says Rabbi Chaninah said whoever reports a saying in the name of the one who said it brings redemption to the world. Megillah 15a based on Esther 2:22.

So when you see "Rabbi A said in the name of Rabbi B" it means that Rabbi A had a tradition that Rabbi B had said something, such as expounding a verse in a certain way. You may see chains that are very long (A said B said C said, etc.), but technically only the name of the first speaker and most recent speaker are needed. See Nazir 52b. So the fact that Rabbi A says something "in the name of" Rabbi B doesn't necessarily mean they ever met or their lives overlapped, but the important point is that the speaker is telling you who he understood the source of his statement to be. In fact, I believe that when something is said "in the name of" Rabbi X it means that the speaker did not hear it directly from Rabbi X, but I can't find a source to confirm that so I could be wrong.

Answer 2

Adding to Avraham's great answer: another epistemic purpose for keeping track of who said what is in the case of difficulties in transmission arising - a time when logic and reasoning are used by the Talmud to repair. Knowing who said what allows the Amoraim to find out what else they said, in order to help them resolve the difficulty.

If Rabbi X says Y but we have reason to believe this isn't all or exactly what he says about Y, and we need more information, this can often be clarified through a formal proof based on what he has said about Z.

E.g. We have a rule that says X is exempt from mitzvot that are in both sets {A} and {B}. We know our Rabbi says that a certain classification of Jew is obligated to do Y, even though Y is in the set of {A} and {B}, and we have lost his reasoning. We need his reasoning to help us figure out another halacha Z, and what he would hold about this classification of Jew being exempt from Z. If the principle is Q, we can work out of Q also applies to Z. Therefore looking at what else we have our Rabbi on record as saying to other situations, we can hopefully prove if he does or does not hold by Q, and therefore what he would say about situation Z.

This is just one example of many similar uses of having the names on record. As you can see, there are many possible loose ends, so a huge amount of intellectual work goes into getting rock solid proofs, which is much of the content of the Talmud.