Rabbi Yehuda and Rabbi Yosei and Rabbi Shimon prohibit one from doing so due to the concern lest the wineskin burst and the contents spill before he has an opportunity to actually separate the teruma and tithes. In that case, when he drank the wine, retroactively, he is found to have drunk untithed produce. Rabbi Meir is not concerned about potential change in the status quo, and Rabbi Yehuda, who is concerned lest the wineskin burst, would all the more so be concerned about potential death.

The Gemara suggests: Reverse the attribution of the statements according to Abaye. Rabbi Meir is concerned about potential death, and Rabbi Yehuda is not concerned about potential death, as it is taught in a baraita: If one utilized his animal as a wall for the sukka, Rabbi Meir deems it unfit and Rabbi Yehuda deems it fit.

The Gemara asks: This is difficult, as there is a contradiction between the statement of Rabbi Meir with regard to sukka, where he is concerned about potential death, and the other statement of Rabbi Meir with regard to separation of teruma and tithes, where he is not concerned lest the wineskin burst. The Gemara answers: Rabbi Meir could have said to you: Death is common, as every living being will eventually die; however, the bursting of the wineskin is not common because it is possible that he gave the wineskin to a guard for protection so that it does not burst until he has the opportunity to separate the required teruma and tithes.

The Gemara asks: This is difficult, as there is a contradiction between the statement of Rabbi Yehuda with regard to sukka, where he is not concerned about potential death, and the other statement of Rabbi Yehuda with regard to separation of teruma and tithes, where he is concerned lest the wineskin burst.

The Gemara answers: The rationale for the opinion of Rabbi Yehuda with regard to tithes is not due to the fact that he is concerned about the potential bursting of the wineskin; rather, he rules that one may not drink the wine because he is not of the opinion that there is a principle of retroactive clarification. The procedure prescribed by Rabbi Meir is based on a fundamental assumption that when the separation is actually performed, the produce that he separates for teruma and tithes at that point is determined retroactively to have been teruma and tithes from the outset. Rabbi Yehuda does not accept this principle. Therefore, one’s subsequent actions do not retroactively determine the original status of the produce.

The Gemara asks: And is Rabbi Yehuda not concerned about the potential bursting of the wineskin? But isn’t there proof from the fact that it teaches in the latter clause of the baraita that the Sages said to Rabbi Meir with regard to tithes: Do you not concede that perhaps the wineskin will burst, and it will be determined retroactively that he is drinking untithed produce? And Rabbi Meir said to the Sages: That possibility is not a concern. When it actually bursts, I will be concerned. This indicates by inference that Rabbi Yehuda, who disagrees with Rabbi Meir, is concerned about the potential bursting of the wineskin.

The Gemara answers that there, it is Rabbi Yehuda who is saying to Rabbi Meir: For me, I am not of the opinion that there is a principle of retroactive clarification, and therefore one cannot separate teruma and tithes after drinking the wine. However, according to your opinion that there is a principle of retroactive clarification, do you not concede that one may not drink wine before separating teruma and tithes due to the concern lest the wineskin burst? Rabbi Meir said to him: When it actually bursts, I will be concerned.

The Gemara asks further: And is Rabbi Yehuda not concerned about potential death? Didn’t we learn in a mishna in tractate Yoma (2a) that the Sages said with regard to the High Priest prior to Yom Kippur: And they would designate another priest in his stead, and since the High Priest performing the Yom Kippur service must be married, Rabbi Yehuda says: They would even designate another wife for him lest his wife die. Apparently, he is concerned about potential death. The Gemara answers: But wasn’t it stated with regard to that mishna that this designation is unique to Yom Kippur, as Rav Huna, son of Rav Yehoshua, said: They established a higher standard with regard to atonement? Therefore, matters that are not a source of concern in other areas of halakha are significant with regard to Yom Kippur.

§ The Gemara asks: Both according to the one who said that an animal is an unfit partition due to the concern lest it die, and according to the one who said that it is due to the concern lest it flee, apparently it is a full-fledged partition by Torah law, and it is the Sages who issued a decree prohibiting its use lest a problem arise. However, if that is so, according to Rabbi Meir an animal used as a covering for a grave should be impure due to the impurity of the covering of a grave. Why, then, did we learn in a mishna (Eiruvin 15a–b) that Rabbi Yehuda says: Even a living creature imparts ritual impurity due to the impurity of the covering of a grave, but Rabbi Meir deems it pure? If according to Rabbi Meir an animal is unfit for use as a partition only due to the concern lest it die or flee, but essentially it is a fit partition, why does it not become impure when used as a covering of a grave?

Rather, Rav Aḥa bar Ya’akov said, contrary to that which was stated above: Rabbi Meir holds that any partition that stands by means of air, i.e., by intangible means, like an animate being, which stands due to its life force, is not a partition. Some say a different version of that which Rav Aḥa bar Ya’akov said: Rabbi Meir holds that any partition that is not established by a person is not a partition.

The Gemara asks: What is the practical difference between the two versions of Rav Aḥa bar Ya’akov’s statement? The Gemara answers: There is a practical difference between them in the case where one establishes a partition with an inflated wineskin. According to the one who said that a partition that stands by means of air is not a partition, this partition also stands by means of air and is therefore unfit. According to the one who said that if it is not established by a person it is not a partition,