the fish fat, which one is permitted to eat even if cooked by gentiles, is the essential element. Therefore, he teaches us that the flour is the essential element, and the gentile has created a new and significant dish, which is consequently prohibited.

Rabbi Abba said: A joining of cooked foods requires an olive-bulk of food. A dilemma was raised before the Sages: Is it enough to have one olive-bulk for all of the household members who are relying on this eiruv, or perhaps must there be a separate olive-bulk for each and every one in the household? Come and hear that which Rabbi Abba said that Rav said: A joining of cooked foods requires an olive-bulk, whether it is cooked for a single person or for one hundred people.

The Gemara comments: We learned in the mishna: If one ate the joining of cooked foods that he prepared, or if it was lost, he may not rely on it and cook with the initial intent to cook for Shabbat; but if he left any part of the eiruv, he may rely on it to cook for Shabbat. The Gemara asks: What is the meaning of: Any part of it? Doesn’t it mean that it is valid although there is not an olive-bulk? The Gemara answers: No, the phrase: Any part of it, means that there is at least an olive-bulk left.

The Gemara attempts to bring another proof. Come and hear: The cooked dish that is required for a joining of cooked foods may be roasted, or even pickled, or well-boiled, or boiled in the regular manner, or may even be Spanish soft sea fish [koleyas ha’ispenin] upon which one poured hot water on the eve of the Festival, rendering it cooked. With regard to its beginning and end, meaning its required size ab initio and after it has been reduced by being partially lost or partially eaten, the eiruv has no required measure. What, is it not that it has no required measure at all, not even a minimum one? The Gemara rejects this: No, it means it does not have a maximum measure, but it does have a minimum measure, namely an olive-bulk.

Rav Huna said that Rav said: A joining of cooked foods requires knowledge, meaning that one must be aware of the eiruv for it to be effective. The Gemara comments: It is obvious that we require the knowledge of the one who prepares the eiruv; the question is: Do we also require the knowledge of the one for whom the eiruv is prepared, or do we not require it?

The Gemara suggests: Come and hear a proof from the following testimonies: Shmuel’s father would prepare an eiruv for the entire city of Neharde’a, and Rabbi Ami and Rabbi Asi would prepare an eiruv for the entire city of Tiberias. Similarly, Rabbi Ya’akov bar Idi would announce: Anyone who did not prepare a joining of cooked foods for himself should come and rely on mine. The Gemara asks: And up to how much may one rely on it, i.e., how far may one be from such an eiruv and still rely upon it? Rav Neḥumi bar Zekharya said in the name of Abaye: One may be as far away as the Shabbat limit.

The Gemara relates: With regard to the blind person who would present mishnayot before Mar Shmuel, the latter observed that he was sad. Mar Shmuel said to him: Why are you sad? He said to him: Because I did not prepare a joining of cooked foods before the Festival. Mar Shmuel said to him: Then rely on mine. In the following year, he once again observed that he was sad. He said to him: Why are you sad? He said to him: Because I did not prepare a joining of cooked foods. Mar Shmuel said to him: If so, you are consistently negligent in this regard. Therefore, for the entire world, i.e., anyone else but you, it is permitted to rely on my eiruv if they forgot to prepare one, but for you it is prohibited to do so, as I did not intend to include such negligent people as yourself in my eiruv.

The Sages taught: If a Festival occurs on Shabbat eve, one may not prepare an eiruv on that day, neither a joining of Shabbat boundaries [eiruv teḥumin] nor a joining of courtyards [eiruv ḥatzerot], for Shabbat. If one did not prepare these before the Festival, he may not do so on the Festival itself.

Rabbi Yehuda HaNasi says: On a Festival that occurs on a Friday, one may prepare an eiruv for a joining of courtyards, but not for a joining of Shabbat boundaries. His reasoning is as follows: There is a distinction between the two types of eiruv because you may prohibit him from a matter that is prohibited to him, e.g., venturing beyond the Shabbat limit, which is prohibited on a Festival as well as Shabbat, but you may not prohibit him from a matter that is permitted to him, e.g., carrying from one domain to another, which is permitted on a Festival. Therefore, on a Festival, one may not prepare a joining of Shabbat boundaries in order to render it permitted to venture beyond the boundary on the Shabbat following the Festival. However, one may prepare a joining of courtyards on the Festival in order to render it permitted to carry from one domain to another on the Shabbat following the Festival.

It was stated that the amora’im disagreed as to the conclusive ruling. Rav said: The halakha is in accordance with the opinion of the first tanna, who said that it is prohibited to prepare both types of eiruvin, and Shmuel said: The halakha is in accordance with the opinion of Rabbi Yehuda HaNasi, and it is permitted to prepare a joining of courtyards on a Festival.

A dilemma was raised before the Sages: Is stating that the halakha is in accordance with the opinion of Rabbi Yehuda HaNasi a leniency or a stringency? The Gemara wonders at this query: It is obvious that he stated it as a leniency. The Gemara explains: The question was asked because Rabbi Elazar sent a message from Eretz Yisrael to the Diaspora: This baraita is not as you teach it in Babylonia, that Rabbi Yehuda HaNasi permits one to prepare a joining of courtyards on a Festival and the Rabbis prohibit it. Rather, the opinions should be reversed, so that Rabbi Yehuda HaNasi prohibits it and the Rabbis permit it. Therefore, the question arose: What is the conclusive ruling for this halakha? Is it lenient or stringent?

The Gemara attempts to cite a proof: Come and hear that Rav Taḥlifa bar Avdimi performed an action in accordance with the opinion of Shmuel, who ruled that the halakha is in accordance with the opinion of Rabbi Yehuda HaNasi, and Rav said in anger about this: The first public ruling of this young Torah scholar is bringing about corruption of the halakha. The Gemara analyzes this statement: Granted, if you say that Rabbi Yehuda HaNasi said it as a leniency, this explains the corruption of the halakha involved, as Rav was angered by a young scholar who relied on his own judgment to issue a lenient ruling on a disputed issue. However, if you say that Rabbi Yehuda HaNasi meant it as a stringency, what corruption of the halakha is there in the young scholar’s ruling?

The Gemara answers: Since it corrupts the behavior of the masses, as, if they refrain from preparing a joining of courtyards on the Festival although it is permitted to do so, they might mistakenly carry from one domain to another on Shabbat,