Is Rav Ashi batrai vis-à-vis Mar Zutra?
On Bava Metzia 15b,
מַאי טַעְמָא? מָר זוּטְרָא אָמַר: נִיחָא לֵיהּ דְּלָא נִקְרְיֵיהּ גַּזְלָנָא. רַב אָשֵׁי אָמַר: נִיחָא לֵיהּ דְּלֵיקוּ בְּהֵמָנוּתֵיהּ.
The Gemara asks: What is the reason that the robber would buy the land he had already sold in order to retroactively uphold the sale? Mar Zutra said: It is preferable for him not to be called a robber by the purchaser when the original owner demands he return the field. Rav Ashi said: It is preferable for him to maintain his reliability, i.e., to be considered an honest person.
The Talmudic Narrator finds a pragmatic difference between the two. Later on, both the assumption of the gemara, and Rav Acha and Ravina, operate within Rav Ashi.
The Rif writes simply that the sugya is like Rav Ashi so the halacha is like him.
זוטרא אמר ניחא ליה דלא נקרייה גזלנא ומשום הכי טרח וזבין לה מנגזל כי היכי דתיקום בידא דלוקח רב אשי אמר ניחא ליה דליקום בהימנותיה מאי בינייהו איכא בינייהו (דף טז.) מתנה מאן דאמר ניחא ליה דליקום בהימנותיה מתנה נמי ניחא ליה דליקום בהימנותיה ומאן דאמר ניחא ליה דלא נקרייה גזלן א"ל מאי גזלי מינך והלכתא כרב אשי דסוגיא דשמעתא כותיה:
Rather than pointing to Rav Acha and Ravina, we can point to the gemara’s question:
וְעַד אֵימַת נִיחָא לֵיהּ דְּלֵיקוּם בְּהֵמָנוּתֵיהּ? אָמַר רַב הוּנָא: עַד שְׁעַת הַעֲמָדָה בַּדִּין.
The Gemara asks: And until when can it be assumed that the robber bought the land because it is preferable for him to maintain his reliability? Rav Huna says: Until the time of standing trial. Once the purchaser takes the robber to court, it is too late for the robber to protect his reputation, as the purchaser has demonstrated that he does not consider the robber to be trustworthy.
which is predicated on reliability rather than not being called a robber.
Tosafot give more reasons. Namely, on 16a, the gemara reads:
יַהֲבַהּ נִהֲלֵיהּ בְּמַתָּנָה, פְּלִיגִי בַּהּ רַב אַחָא וְרָבִינָא. חַד אָמַר: מַתָּנָה כִּירוּשָּׁה, דְּהָא מִמֵּילָא. וְחַד אָמַר: מַתָּנָה כְּמֶכֶר, דְּאִי לָאו דְּטָרַח וְאַרְצִי קַמֵּיהּ לָא הָוֵי יָהֵיב לֵיהּ מַתָּנָה, לְהָכִי טְרַח וְאַרְצִי קַמֵּיהּ, כִּי הֵיכִי דְּלֵיקוּם בְּהֵמָנוּתֵיהּ.
With regard to a case where the robbery victim gave the land as a gift to the robber, Rav Aḥa and Ravina disagree. One says that a gift has the same status as an inheritance, as it is also acquired passively, and one says that a gift has the same status as a sale. This is because were it not for the fact that the robber took the trouble to ingratiate himself with the owner, he would not have given it to him as a gift. It is clearly for this reason that the robber took the trouble to ingratiate himself with him, i.e., in order to validate the sale and thereby maintain his reliability.
Tosafot write, based on the last phrase:
ארצי קמיה כי היכי דליקום בהימנותיה - משמע דהכי הלכתא מדלא נקט לישנא דלא נקרייה גזלן ועוד דהלכה כרב אשי דהוא בתראה וגדול בחכמה ובמנין:
The implication is that this is the halacha, since it (the Talmud) did not utilize the language “that he should not be called a robber”. And furthermore, that the halacha is like Rav Ashi, since he is later (batra’a) and is greater in wisdom and in numbers.
The Rosh adds on to the Rif, but doesn’t mention batra’a. Rather, he writes:
מ"ט מר זוטרא אמר ניחא ליה לאיניש דלא לקריוהו גזלנא. רב אשי אמר ניחא ליה לאיניש דליקו בהימנותיה מאי בינייהו א"ב מתנה. מ"ד ניחא ליה דליקו בהימנותיה גבי מתנה נמי ניחא ליה דליקו בהימנותיה. ומ"ד ניחא ליה דלא לקריוהו גזלן א"ל מאי גזלי מינך. והלכתא כוותיה דרב אשי. מדקאמר סתמא דגמרא להכי טרח קמיה דניחא ליה דליקו בהימנותיה. ועוד דרב אשי הוי גדול בחכמה ובמנין טפי ממר זוטרא:
… and the halacha is like Rav Ashi, since the Stamma de-Gemara (Talmudic Narrator) wrote “therefore he endeavored before him, for he would prefer to maintain his reliability.” And further, since Rav Ashi was greater in wisdom and numbers more than Mar Zutra.
I think Rosh thought of my issue, which is why he left out the batra’a claim, listing only wisdom and numbers. (Indeed, keep reading a bit in the Rosh, and he discusses Rav Hai Gaon’s reversal, and says that we rule against fifth generation Rav Pappa because שוב חזר בו בתשובה ופסק הלכתא כרב. משום דחזינן מר זוטרא ורב אשי ורב אחא ורבינא דאמוראי בתראי אינון ושקלו וטרו אליבא דרב. So he will say batrai where it does apply)
The big difficulty / issue is that Mar Zutra really is a contemporary of Rav Ashi. They are both sixth-generation Amoraim. It is just that he was head in Pumpedita academy, while Rav Ashi was head in Mata Mechasya (/Sura) academy.
It is possible that the Rif was confounded by Mar Zutra Chasida, who is a different person, and is indeed earlier, third-generation.
Since Rav Ashi isn’t later, there are three factors:
the language of the gemara, when describing Rav Huna
wisdom
numbers
I don’t know how to quantify Wisdom, to say that Rav Ashi was cleverer that Mar Zutra. Maybe this is a tradition? Maybe we can see how often he wins disputes on the merit? Do we assume based on prominence? Maybe because Rav Ashi was a redactor, who produced the gemara? But Mar Zutra may also be a redactor. That is:
I think this is because he is acting as a redactor of the Pumbeditan Talmud, just as Rav Ashi acted as redactor of the Suran Talmud. And so, occasionally, we’ll get a peek at the alternate gemara. And in any given sugya, it might be from Sura or from Pumbedita.
Maybe Rav Ashi heeded והעמידו תלמידים הרבה from Pirkei Avot to a greater degree, so his followers are greater in minyan? While Pumbedita existed, it may not have been so central.
In terms of the Stamma deGemara according with Rav Ashi, I’d note that it is particularly the Stamma. I don’t think that Rav Acha and Ravina, and Rav Huna, all need to use that specific Rav Ashi formulation.
But, if Rav Ashi acts as redactor, the Suran Stamma before us works within his view. It could be that in Pumbedita, they had the same scholars weighing in, but formulated it with a Mar Zutran approach.