Talmud - Eruvin 46a עירובין מ״ו א׳

The Gemara raises a difficulty: If the water was previously not in its current state, all the more so should it be considered as something that came into being [nolad] on the Festival, and consequently it is prohibited to carry it. Something that came into being or assumed its present form on Shabbat or Festivals is considered set-aside [muktze] and may not be handled on Shabbat or Festivals.

Rather, we should say: The water in clouds is in constant motion and therefore does not acquire residence there. The Gemara comments: Now that you have arrived at this answer, the ocean should also not be difficult for you, as the water in the ocean is also in constant motion. And it was taught in a baraita: Flowing rivers and streaming springs are like the feet of all people, as their waters do not acquire residence in any particular place. The same law also applies to clouds and seas.

Rabbi Ya’akov bar Idi said that Rabbi Yehoshua ben Levi said: The halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri, that one who was asleep at the beginning of Shabbat may travel two thousand cubits in every direction. Rabbi Zeira said to Rabbi Ya’akov bar Idi: Did you hear this halakha explicitly from Rabbi Yehoshua ben Levi, or did you understand it by inference from some other ruling that he issued? Rabbi Ya’akov bar Idi said to him: I heard it explicitly from him.

The Gemara asks: From what other teaching could this ruling be inferred? The Gemara explains: From that which Rabbi Yehoshua ben Levi said: The halakha is in accordance with the lenient opinion with regard to an eiruv.

The Gemara asks: Why do I need both? Why was it necessary for Rabbi Yehoshua ben Levi to state both the general ruling that the halakha is in accordance with the lenient opinion with regard to an eiruv, and also the specific ruling that the halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri on this issue?

Rabbi Zeira said: Both rulings were necessary, as had he informed us only that the halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri, I would have said that the halakha is in accordance with him whether this is a leniency, i.e., that a sleeping person acquires residence and may walk two thousand cubits in every direction, or whether it is a stringency, i.e., that ownerless utensils acquire residence and can be carried only two thousand cubits from that place. Consequently, he teaches us that the halakha is in accordance with the lenient opinion with regard to an eiruv, so that we rule in accordance with Rabbi Yoḥanan ben Nuri only when it entails a leniency.

The Gemara asks: Let him state only that the halakha is in accordance with the lenient opinion with regard to an eiruv. Why do I need the statement that the halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri?

The Gemara answers: This ruling was necessary as well, for had he informed us only that the halakha is in accordance with the lenient opinion with regard to an eiruv, it might have entered your mind to say that this statement applies only to disputes in which a single authority disagrees with another single authority, or several authorities disagree with several other authorities. But when a single authority maintains a lenient opinion against several authorities who maintain a more stringent position, you might have said that we do not rule in his favor. Hence, it was necessary to state that the halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri although he disputes the Rabbis.

Rava said to Abaye: Now, since the laws of eiruvin are rabbinic in origin, what reason is there for me to differentiate between a disagreement of a single authority with a single authority and a disagreement of a single authority with several authorities?

Rav Pappa said to Rava: Is there no difference with regard to rabbinic laws between a disagreement of a single authority with a single authority, and a disagreement of a single authority with several authorities?

Didn’t we learn in a mishna that Rabbi Elazar says: Any woman who passed three expected menstrual cycles without experiencing bleeding is presumed not to be menstruating. If afterward she sees blood, it is enough that she be regarded as ritually impure due to menstruation from the time that she examined herself and saw that she had a discharge, rather than retroactively for up to twenty-four hours. The Rabbis, however, maintain that this halakha applies only to an older woman or to a woman after childbirth, for whom it is natural to stop menstruating, but not to a normal young woman for whom three periods have passed without bleeding.

And it was taught in a baraita: It once happened that Rabbi Yehuda HaNasi ruled that the halakha is in accordance with the opinion of Rabbi Elazar. After he remembered that Rabbi Elazar’s colleagues disagree with him on this matter and that he had apparently ruled incorrectly, he nonetheless said: Rabbi Elazar is worthy to rely upon in exigent circumstances.

The Gemara comments: What is the meaning of: After he remembered? If you say that it means after he remembered that the halakha is not in accordance with the opinion of Rabbi Elazar but rather in accordance with the opinion of the Rabbis, then how could he rule in accordance with him even in exigent circumstances, given that the halakha had been decided against him?

Rather, it must be that the halakha had not been stated on this matter, neither in accordance with the opinion of Rabbi Elazar, nor in accordance with the opinion of the Rabbis. And after he remembered that it was not a single authority who disagreed with Rabbi Elazar, but rather several authorities who disagreed with him, he nonetheless said: Rabbi Elazar is worthy to rely upon in exigent circumstances. This demonstrates that even with a dispute that involves a rabbinic decree, such as whether a woman is declared ritually impure retroactively, there is room to distinguish between a disagreement of a single authority and a single authority, and a disagreement of a single authority and several authorities.

Rav Mesharshiya said to Rava, and some say it was Rav Naḥman bar Yitzḥak who said to Rava: Is there no difference with regard to rabbinic laws between a disagreement of a single authority with a single authority, and a disagreement of a single authority with several authorities?

Wasn’t it was taught in a baraita: If a person receives a proximate report that one of his close relatives has died, he practices all the customs of the intense seven day mourning period as well as the customs of the thirty day mourning period. But if he receives a distant report, he practices only one day of mourning.

What is considered a proximate report, and what is considered a distant report? If the report arrives within thirty days of the close relative’s passing, it is regarded as proximate, and if it arrives after thirty days it is considered distant; this is the statement of Rabbi Akiva. But the Rabbis say: Both in the case of a proximate report and in the case of a distant report, the grieving relative practices the seven-day mourning period and the thirty-day mourning period.

And Rabba bar bar Ḥana said that Rabbi Yoḥanan said: Wherever you find that a single authority is lenient with regard to a certain halakha and several other authorities are stringent, the halakha is in accordance with the words of the stringent authorities, who constitute the majority, except for here, where despite the fact that the opinion of Rabbi Akiva is lenient and the opinion of the Rabbis is more stringent, the halakha is in accordance with the opinion of Rabbi Akiva.

And Rabbi Yoḥanan holds like Shmuel, as Shmuel said: The halakha is in accordance with the lenient opinion with regard to mourning practices, i.e., wherever there is a dispute with regard to mourning customs, the halakha is in accordance with the lenient opinion.

From here the Gemara infers: It is only with regard to mourning practices that the Sages were lenient, but in general, with regard to other areas of halakha, even in the case of rabbinic laws there is a difference between a disagreement of a single authority with a single authority and a disagreement of a single authority with several authorities. This being the case, Rabbi Yehoshua ben Levi did well to rule explicitly that the halakha is in accordance with the opinion of Rabbi Yoḥanan ben Nuri, even though he is a single authority who ruled leniently in dispute with the Rabbis.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Eruvin 46a explores why moving water like clouds and seas avoids muktze status, then debates the accepted lenient ruling on eiruv and Shabbat travel limits.