Our Gemara on Amud Aleph discusses a dispute regarding how long it takes for a convert to be seen by the community as a regular member of the tribe, which has halakhic implications in terms of how many generations would be allowed to marry a mamzer. If the community thought of the convert as purely Jewish, it would be maris ayin (the appearance of sin), as a full member of the tribe may not marry a mamzer. Some say it takes until people no longer remember that he was a convert, and others say it requires ten generations.

This discussion may be related to a dispute that Rav and Shmuel had concerning Yisro's reaction to hearing about the fall of Pharaoh and his empire to the Jews. The verse uses a non-typical word to express what would seem, from the context, to be Yisro's joy (Shemos 18:9):

וַיִּ֣חַדְּ יִתְר֔וֹ עַ֚ל כׇּל־הַטּוֹבָ֔ה

Yisro rejoiced over all the good.

While the etymology of יִּ֣חַדְּ (Vayichad) is from "chedvah" (joy), it could also be related to "chad" (sharp). Therefore, Talmud Sanhedrin (94a) needs to figure out where the sharpness that was intermingled with Yisro’s expression of joy can be found:

ויחד יתרו רב ושמואל רב אמר שהעביר חרב חדה על בשרו ושמואל אמר שנעשה חדודים חדודים כל בשרו אמר רב היינו דאמרי אינשי גיורא עד עשרה דרי לא תבזה ארמאי קמיה

It is written in the previous verse: “Vayyiḥad Yisro for all the goodness that the Lord had done to Israel, whom He had delivered out of the hand of Egypt” (Exodus 18:9). Rav and Shmuel disagreed with regard to the meaning of vayyiḥad. Rav says: He passed a sharp [ḥad] sword over his flesh, i.e., he circumcised himself and converted. And Shmuel says: He felt as though cuts [ḥiddudim] were made over his flesh, i.e., he had an unpleasant feeling due to the downfall of Egypt. Rav says with regard to this statement of Shmuel that this is in accordance with the adage that people say: With regard to a convert, for ten generations after his conversion, one should not disparage a gentile before him and his descendants, as they continue to identify somewhat with gentiles and remain sensitive to their pain.

Parenthetically, this reminds me of a well-known story about Rav Chaim Pinchas Sheinberg ZT’L, who apparently had a regular American childhood along with following certain sports teams. According to the story, decades after becoming a godol, he shared with a talmid that he is so happy that the Yankees won the World Series – not because they won, but because they won and he had no reaction, indicating that he finally got over his ties and attachment to this frivolous pastime!

In any case, one could argue that Shmuel's opinion in Sanhedrin would be aligned with the opinion in our Gemara, allowing a convert ten generations before maris ayin prohibits marrying a mamzer.

Let us analyze the foundation of the dispute between Rav and Shmuel. Rav cannot fathom that Yisro was unable to let go of his emotional attachments and identification with his old secular culture. Perhaps even further, Yisro made a clean break via the pain and sacrifice of a bris milah. We might even say that Yisro was symbolically cutting out his old gentile identification. However, Shmuel seems to hold more pragmatically, "You can take the boy out of Midian, but you can't take Midian out of the boy," to paraphrase the American aphorism about the country boy. Shmuel says it takes ten generations to change one’s deep affiliations despite devout intention and sacrifice, and Yisro’s pain was over hearing the downfall of his old "team," so to speak, the Egyptians.

We find two other disputes between Rav and Shmuel that may also hinge on this idea.

In Pesachim (116a), Rav and Shmuel disagree about when the Exodus story begins:

מַתְחִיל בִּגְנוּת וּמְסַיֵּים בְּשֶׁבַח. מַי בִּגְנוּת? רַב אָמַר: ״מִתְּחִלָה עוֹבְדֵי עֲבוֹדָה זָרָה הָיוּ אֲבוֹתֵינוּ״. [וּשְׁמוּאֵל] אָמַר: ״עֲבָדִים הָיִינוּ״.

It was taught in the mishna that the father begins his answer with disgrace and concludes with glory. The Gemara asks: What is the meaning of the term: With disgrace? Rav said that one should begin by saying: At first, our forefathers were idol worshipers, before concluding with words of glory. And Shmuel said: The disgrace with which one should begin his answer is: We were slaves in Egypt.

If we follow the reasoning of our earlier analysis, we can say that Rav holds the convert must utterly uproot any vestiges of idolatry. Therefore, when we recount the Jewish experience, we start with the disgrace of our ancestors in order to renounce their idol worship. Shmuel either feels that it is against human nature or will cause too much anguish, as he said in regard to disparaging an Aramite in front of a convert. Therefore, Shmuel holds that we start the Exodus story with slavery.

Similarly, in Shabbos (33b), Rav and Shmuel argue about steps Yaakov took in Shechem to reform and uplift the neighborhood after having emerged safely from his encounter with Esau.

אֲמַר: הוֹאִיל וְאִיתְרְחִישׁ נִיסָּא אֵיזִיל אַתְקֵין מִילְּתָא. דִּכְתִיב: ״וַיָּבֹא יַעֲקֹב שָׁלֵם״, וְאָמַר רַב: שָׁלֵם בְּגוּפוֹ, שָׁלֵם בְּמָמוֹנוֹ, שָׁלֵם בְּתוֹרָתוֹ. ״וַיִּחַן אֶת פְּנֵי הָעִיר״, אָמַר רַב: מַטְבֵּעַ תִּיקֵּן לָהֶם, וּשְׁמוּאֵל אָמַר: שְׁוָוקִים תִּיקֵן לָהֶם, וְרַבִּי יוֹחָנָן אָמַר: מֶרְחֲצָאוֹת תִּיקֵן לָהֶם. אֲמַר: אִיכָּא מִלְּתָא דְּבָעֵי לְתַקּוֹנֵי? אֲמַרוּ לֵיהּ: אִיכָּא דּוּכְתָּא דְּאִית בֵּיהּ סְפֵק טוּמְאָה

Rabbi Shimon said: Since a miracle transpired for me, I will go and repair something for the sake of others in gratitude for God’s kindness, as it is written: "And Jacob came whole to the city of Shechem, which is in the land of Canaan when he came from Paddan-aram; and he graced the countenance of the city" (Genesis 33:18). Rav said, the meaning of: And Jacob came whole is: Whole in his body, whole in his money, whole in his Torah. And what did he do? And he graced the countenance of the city; he performed gracious acts to benefit the city. Rav said: Jacob established a currency for them. And Shmuel said: He established marketplaces for them.

According to Rav, an entire overhaul was necessary, symbolic of changing the currency, which essentially means changing the government, representing complete social reform. On the other hand, Shmuel's understanding of Yaakov’s contribution to the betterment of Shechem society was less ambitious: keep the currency the same, just make marketplace reforms. In other words, work with what you have and change more slowly.

One final parallel dispute comes from Shabbos (22a) regarding whether one may light from one Chanukah lamp to another or use fringes from one tzitzis garment for another:

אִיתְּמַר: רַב אָמַר אֵין מַדְלִיקִין מִנֵר לְנֵר, וּשְׁמוּאֵל אָמַר מַדְלִיקִין. רַב אָמַר אֵין מַתִּירִין צִיצִית מִבֶּגֶד לְבֶגֶד, וּשְׁמוּאֵל אָמַר מַתִּירִין מִבֶּגֶד לְבֶגֶד. רַב אָמַר אֵין הֲלָכָה כְּרַבִּי שִׁמְעוֹן בִּגְרִירָה, וּשְׁמוּאֵל אָמַר הֲלָכָה כְּרַבִּי שִׁמְעוֹן בִּגְרִירָה.

Rav said: One may not light from one Hanukkah lamp to another lamp. And Shmuel said: One may light in that manner. The Gemara cites additional disputes between Rav and Shmuel. Rav said: One may not untie ritual fringes from one garment in order to affix them to another garment. And Shmuel said: One may untie them from one garment and affix them to another garment.

According to Rav, not allowing a transfer from one lamp to another is a manifestation of his standard of making a dramatic, clean break, with nothing from the past. Similarly, Shmuel allows for the old fire and the old fringes to be added onto a new garment. Shmuel allows for taking parts of the old and transitioning gradually to the new.