Talmud - Eruvin 9b עירובין ט׳ ב׳

The Gemara provides an alternative explanation of Rabbi Yoḥanan’s statement. Rav Ashi said: According to Rabbi Yoḥanan, carrying in the area between the side posts is actually permitted. The dispute between Rabban Shimon ben Gamliel and the Rabbis concerning the principle of lavud is in a case where there was an alleyway that one lined with side posts, each positioned less than four handbreadths from the next, and the side posts extend for a length of four cubits.

According to Rabban Shimon ben Gamliel, who said that for a gap of up to four handbreadths we say that the principle of lavud applies, all the side posts are considered a single side post, and since the side post in that case is four cubits long, it is considered a separate alleyway; therefore, it requires an additional side post to permit carrying in it. And according to the Rabbis, who say that we do not say that the principle of lavud applies unless the gap is less than three handbreadths, this area does not require an additional side post to permit carrying within it.

The Gemara asks: And even according to the opinion of Rabban Shimon ben Gamliel, why is another side post required? Let it have the same legal status as a side post that is visible from the outside, protruding from the wall of the alleyway, but appears to be even with the wall from the inside. Since it is evident from the outside that it is a side post and not part of the building, carrying is permitted there.

The Gemara answers: As Rav Ashi’s reason is only according to the opinion of Rabbi Yoḥanan, when Ravin came from Eretz Yisrael to Babylonia, didn’t he say that Rabbi Yoḥanan said: If a side post is visible from the outside, protruding from the wall of the alleyway, but it appears to be even with the wall from the inside, it is not considered to have the legal status of a side post?

An amoraic dispute was stated: If a side post is visible from the inside, protruding from the wall of the alleyway, but it appears to be even with the wall from the outside, it is considered a side post. However, if a side post is visible from the outside protruding from the wall, but it appears to be even with the wall from the inside, there is a disagreement between Rabbi Ḥiyya and Rabbi Shimon, son of Rabbi Yehuda HaNasi, with regard to its status. One said: It is considered to have the legal status of a side post. And the other one said: It is not considered to have the legal status of a side post.

The Gemara clarifies: Conclude that Rabbi Ḥiyya is the one who said that it is considered to have the legal status of a side post, as Rabbi Ḥiyya taught: In the case of a wall at the entrance to an alleyway whose one side is more recessed than the other, whether the recess is visible from outside the alleyway but appears to be even from the inside, or the recess is visible from the inside but appears to be even from the outside, it is considered to have the legal status of a side post. The Gemara states: Indeed, conclude that Rabbi Ḥiyya is the one who said it has the legal status of a side post.

The Gemara rejects this conclusion: And Rabbi Yoḥanan, who explicitly said that a side post of that kind is not considered a side post, did he not hear this halakha? The Tosefta was widely known. Rather, he heard it, but he does not hold in accordance with it. Perhaps, then, Rabbi Ḥiyya also does not hold in accordance with it.

The Gemara answers: What is this comparison? Granted, Rabbi Yoḥanan does not hold in accordance with that halakha. That is why he did not teach it. But Rabbi Ḥiyya, if it is true that he does not hold in accordance with it, why would he teach it?

Rabba bar Rav Huna said: If a side post is visible from the outside, protruding from the wall of the alleyway, but appears to be even with the wall from the inside, it is considered to have the legal status of a side post. Rabba said: And we raise an objection to our own halakha from a mishna: With regard to a small courtyard that was breached along the entire length of one of its walls so that it opens into a large courtyard, in the large one it is permitted to carry and in the small one it is prohibited to carry. This is because the breach is considered an entrance of the large courtyard. The wall of the smaller courtyard was breached along its entire length, therefore there is no visible partition from inside the smaller courtyard. However, the partition is noticeable from the outside, i.e., in the large courtyard, since the breach is flanked on both sides by the remaining segments of the wall of the large courtyard. And if it is so, that a partition that is visible from the outside is considered a partition, carrying in the small courtyard should also be permitted in this case, as the wall is visible from the outside but appears to be even from the inside.

Rabbi Zeira said: This mishna is referring to a case where the walls of the small courtyard protrude into the large one, i.e., the breached wall of the small courtyard is not in line with the wall of the large one. Therefore, even when viewed from the outside there are no walls visible, and that is why carrying is prohibited there.

The Gemara asks: And let us say that the principle of lavud applies, and then carrying will be permitted even in the small courtyard. The ends of the breached wall should be considered attached to the side walls of the large courtyard, rendering the wall of the large courtyard visible. Then it will be permitted to carry in the small courtyard based on the principle governing side posts visible from the outside.

And if you say that the walls of the smaller courtyard are too separate from the walls of the larger courtyard, such that the distance between the walls is too great for the principle of lavud to apply, didn’t Rav Adda bar Avimi teach before Rabbi Ḥanina: The small courtyard of which they speak is referring even to one ten cubits wide; the large one is referring even to one eleven cubits wide? Apparently, this halakha applies even when the difference in width between the courtyards is a single cubit, which is six handbreadths. Assuming the small courtyard is located equidistant from the ends of the large courtyard, only three handbreadths separate it on each side from the wall of the large one. Therefore, the principle of lavud applies.

Ravina said: It is a case where the walls of the smaller courtyard are separated from this wall of the larger courtyard by two handbreadths and from this wall of the larger courtyard on the other side by four handbreadths. Since there is a distance of more than three handbreadths, the principle of lavud does not apply.

The Gemara asks: And let us say that the principle of lavud applies from one direction, then carrying will be permitted even in the small courtyard.

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

Eruvin 9b explores Rav Ashi’s take on Rabbi Yoḥanan’s ruling, debating lavud and the validity of side posts in an alleyway’s eruv.