ורבנן התם כי היכי דלא לזלזולי ביה:

And the Rabbis hold that there, the first day is not observed as a Festival by Torah law but due to rabbinic decree, so that people will not demean the day in future years and end up desecrating the Festival should the witnesses come on time. However, by Torah law it is an ordinary weekday, and therefore one can establish two separate eiruvin for the two days.

ועוד אמר רבי יהודה וכו׳:

We learned in the mishna that in addition to his ruling with regard to eiruvin for the two days of Rosh HaShana, Rabbi Yehuda said further that the two days can be split with regard to a basket of tevel produce and an egg laid on the first day of the Festival.

וצריכא דאי אשמעינן ראש השנה בהא קאמר רבי יהודה משום דלא קעביד מידי אבל כלכלה דמיחזי כמתקן טיבלא אימא מודה להו לרבנן

The Gemara comments: And it was necessary to teach us all three laws, as they could not have been derived from one another. As, if he had only taught us the halakha with regard to establishing an eiruv for the two days of Rosh HaShana, one might have said that only in this case does Rabbi Yehuda say his ruling because in this case one does not actually do anything on the Festival itself. But in the case of a basket, where it appears as though one is rendering tevel fit on a Festival, say that Rabbi Yehuda concedes to the Rabbis that it is decreed prohibited.

ואי אשמעינן הני תרתי משום דליכא למיגזר עלייהו אבל ביצה דאיכא למיגזר בה משום פירות הנושרין ומשום משקין שזבו אימא מודה להו לרבנן צריכא:

And had he taught us only these two halakhot, we might have said that Rabbi Yehuda is lenient because there is no reason to issue a decree prohibiting them, as the potential prohibitions involved are not so severe. But in the case of an egg that was laid on the first day of a Festival, where there is reason to issue a decree prohibiting it, as explained in tractate Beitza , because of fruit that fall from a tree or due to liquids that oozed from fruit on a Festival, both of which the Sages prohibited as a safeguard against violating Torah prohibitions, say that Rabbi Yehuda concedes to the opinion of the Rabbis, which maintains that this egg may not be eaten even on the second day of the Festival. It was therefore necessary to teach us all three cases.

תניא כיצד אמר רבי יהודה מתנה אדם על הכלכלה ביום טוב ראשון ואוכלה בשני היו לפניו שתי כלכלות של טבל אומר אם היום חול ולמחר קדש תהא זו תרומה על זו ואם היום קדש ולמחר חול אין בדברי כלום וקורא עליה שם ומניחה

It was taught in a baraita:

How is one to carry out what Rabbi Yehuda said, that a person may make a condition with regard to a basket of tevel produce on the first day of the Festival and then eat the produce on the second day? If there were two baskets of tevel produce before him, he says as follows: If today is an ordinary weekday and tomorrow is sanctified, let this basket be teruma for that basket; and if today is sanctified and tomorrow is an ordinary weekday, my statement has no significance. And he bestows upon the basket the name of teruma, and sets it aside.

ולמחר הוא אומר אם היום חול תהא זו תרומה על זו ואם היום קדש אין בדברי כלום וקורא עליה שם ואוכלה רבי יוסי אוסר וכן היה רבי יוסי אוסר בשני ימים טובים של גליות

And on the next day he says as follows: If today is an ordinary weekday, let this basket be teruma for that basket; and if today is sanctified, my statement has no significance. And He bestows upon the basket the name of teruma, and he may then eat the produce in the other basket, as teruma has definitely been separated on a weekday. Rabbi Yosei prohibits this. And, so too, Rabbi Yosei would prohibit this procedure even on the two Festival days of the Diaspora, even though the second day is only observed because of a doubt as to the proper day on which to observe the Festival.

ההוא בר טביא דאתא לבי ריש גלותא דאתציד ביום טוב ראשון של גליות ואשתחיט ביום טוב שני

The Gemara relates that a particular young deer was brought to the house of the Exilarch. The deer was trapped by a gentile on the first day of a Festival observed in the Diaspora and slaughtered on the second day of the Festival. The question arose whether it was permitted to eat it, based on the fact that one of these two days was certainly an ordinary weekday.

רב נחמן ורב חסדא אכלו רב ששת לא אכל אמר רב נחמן מאי אעביד ליה לרב ששת דלא אכיל בישרא דטביא אמר ליה רב ששת והיכי איכול דתני איסי ואמרי לה איסי תני וכן היה רבי יוסי אוסר שני ימים טובים של גליות

Rav Naḥman and Rav Ḥisda ate from it, but Rav Sheshet did not eat from it. Rav Naḥman said in a jesting manner: What can I do for Rav Sheshet, who does not eat deer meat? Rav Sheshet said to him: How can I eat it, as Isi taught, and some say that this should be read as a question: Didn’t Isi teach: And, so too, Rabbi Yosei would prohibit this procedure even on the two Festival days of the Diaspora?

אמר רבא ומאי קושיא דילמא הכי קאמר וכן היה רבי יוסי אוסר בשני ימים טובים של ראש השנה בגולה אי הכי של גליות בגולה מיבעי ליה

Rava said: What is the difficulty? Perhaps this is what he said: And, so too, Rabbi Yosei would prohibit this procedure even on the two Festival days of Rosh HaShana in the Diaspora, but with regard to the two days of other Festivals observed in the Diaspora, he too would agree with Rabbi Yehuda and permit it. They said to him: If so, the phrase of the Diaspora is inappropriate. It should have said in the Diaspora.

אמר רב אסי ומאי קושיא דילמא הכי קאמר וכן היה רבי יוסי עושה איסור שני ימים טובים של גליות כשני ימים טובים של ראש השנה לרבנן דשרו

Rav Asi said: What is the difficulty? Perhaps this is what he said: And so too, Rabbi Yosei would treat the prohibition of such a procedure on the two Festival days of the Diaspora as on the two Festival days of Rosh HaShana, according to the opinion of the Rabbis, who permit it. In any case, the proof from this baraita is inconclusive.

אשכחיה רב ששת לרבה בר שמואל אמר ליה תני מר מידי בקדושות אמר ליה תנינא מודה רבי יוסי בשני ימים טובים של גליות אמר ליה אי משכחת להו לא תימא להו ולא מידי

The Gemara further relates that afterward Rav Sheshet met Rabba bar Shmuel and said to him: Has the Master learned anything with regard to the two sanctities of a Festival and the like? Rabba bar Shmuel said to him: We have learned that Rabbi Yosei concedes with regard to the two Festival days of the Diaspora. Rav Sheshet said to him: If you happen to meet Rav Naḥman and Rav Ḥisda, who disagreed with me and ate the deer in the Exilarch’s house, do not tell them anything of what you just told me, lest they use this tannaitic source to embarrass me about my refusal to eat.

אמר רב אשי לדידי אמר לי אמימר ההוא בר טביא לאו איתצודי איתציד

Rav Ashi said: Ameimar told me that the deer was not trapped on the Festival;