Talmud - Eruvin 78b עירובין ע״ח ב׳

Rav Yosef further asked: If the ladder resting against the wall was less than four handbreadths wide, and one dug out grooves in the wall as extensions of the rungs of the ladder to complete the measure, how high must this hollowed-out section be to consider the ladder a valid passageway between the two courtyards? Rabba said to him: If it is ten handbreadths high and four handbreadths wide, it is considered a passageway.

Rav Yosef said to him: If there was no ladder, and one dug out the entire ladder in the wall, so that all the steps are grooves in the wall, how much must he hollow out? Rabba said to him: Those steps must reach the full height of the wall. Rav Yosef asked: And what is the difference in this case? Why must the steps reach higher in this case than in the case where the hollowed-out section was merely an extension of an existing ladder? Rabba said to him: There, where there is a ladder, it is easy to climb to the top of the wall; however, here, where there are only grooves in the wall, it is not easy to climb. If one cannot reach the top of the wall, the steps are not considered a passageway between the courtyards.

Rav Yosef raised a dilemma before Rabba: If one designated a tree as a ladder, what is the halakha? Given that it is prohibited to climb a tree on Shabbat, if a tree stands next to a wall and it is easy to climb, is it considered with regard to the halakhot of Shabbat as an opening in the wall that can serve as a passageway between the two courtyards?

Let the dilemma be raised according to the opinion of Rabbi Yehuda HaNasi, who maintains that a joining of Shabbat boundaries [eiruv teḥumin] placed in a tree is valid; and let the dilemma be raised according to the opinion of the Rabbis, who disagree.

The Gemara elaborates: Let the dilemma be raised according to the previously stated opinion of Rabbi Yehuda HaNasi. Rabbi Yehuda HaNasi only stated there that with regard to anything that is prohibited on Shabbat due to a rabbinic decree [shevut], the Sages did not prohibit it during twilight. Therefore, in Rabbi Yehuda HaNasi’s opinion, it is permitted to use an eiruv that was deposited in a tree, as the use of a tree is prohibited on Shabbat by rabbinic decree. However, this applies only in that case, as the eiruv takes effect during the twilight period. Since there is doubt with regard to whether that period is considered day or night, the decree is not in force, and the eiruv is therefore valid. However, in this case, where the opening must be valid for the entire day, Rabbi Yehuda HaNasi would not rule that the decree does not apply. Since it is prohibited by rabbinic decree to climb a tree on Shabbat, a tree cannot be considered a valid passageway.

Or perhaps it may be argued that even according to the opinion of the Rabbis, this tree is considered an opening. They may have said that a joining of Shabbat boundaries placed in a tree is not valid only because the eiruv must actually be accessible during twilight, and in that case it is not, due to the rabbinic decree. However, in this case, where it is not necessary to make actual use of the tree, they would agree that a tree that serves as a ladder is a valid entrance, but a lion crouches upon it. Just as a lion crouching at an opening does not thereby nullify its status as an entrance, although in practice no one can pass through it, so too, in the case of the tree, the prohibition against climbing it does not nullify its status as a passageway.

Rav Yosef further inquired: If one designated a tree worshipped as part of idolatrous rites [asheira], from which it is forbidden to derive benefit, as a ladder, what is the halakha? Is it considered a valid passageway in the wall with regard to the halakhot of Shabbat? Here, too, let the dilemma be raised according to the opinion of Rabbi Yehuda, and let the dilemma be raised according to the opinion of the Rabbis.

The Gemara elaborates: Let the dilemma be raised according to the previously stated opinion of Rabbi Yehuda. Rabbi Yehuda only stated there that it is permitted to acquire, i.e., make use of, a house for the purposes of establishing an eiruv even if it is among the items from which it is prohibited to derive benefit, such as a grave. This statement applies only there, with regard to acquiring an eiruv in that location, since after the eiruv has acquired a place of residence for him, it is not important to him that it is guarded. He requires the grave only for the moment of the acquisition of the eiruv, and what happens to it afterward is of no consequence to him. However, here, since one desires the continued presence of the ladder, it is possible that even Rabbi Yehuda would agree that one may not rely on an asheira, as one may not climb and make use of it, since it is prohibited to derive benefit from it.

Or perhaps it may be argued that even though according to the opinion of the Rabbis it is prohibited to use a grave to acquire an eiruv, here they would agree that the asheira is an opening, but a lion crouches upon it, and this does not nullify its status as an opening.

Rabba said to him: A tree is permitted for use as a ladder, but an asheira is prohibited. Rav Ḥisda strongly objects to this: On the contrary, a tree, with regard to which a Shabbat prohibition causes it to be prohibited, should be prohibited, so that it will not be said that a Shabbat prohibition has been disregarded in a case involving the halakhot of Shabbat.

And the converse is also true: An asheira, with regard to which something else, a halakha unrelated to the halakhot of Shabbat, causes it to be prohibited, should not be prohibited. Rather, it should be considered an opening with regard to Shabbat.

Indeed, it was also stated: When Ravin came from Eretz Yisrael to Babylonia, he said that Rabbi Elazar said, and some say that Rabbi Abbahu said that Rabbi Yoḥanan said: Anything with regard to which a prohibition of Shabbat causes it to be prohibited is prohibited; and conversely, anything with regard to which something else causes it to be prohibited is permitted.

However, in contrast to Rav Yosef, Rav Naḥman bar Yitzḥak taught as follows: These questions are indeed dependent on the known disputes. Whether a tree serving as a ladder constitutes a valid opening is the subject of a dispute between Rabbi Yehuda HaNasi and the Rabbis; Rabbi Yehuda HaNasi permits it and the Rabbis prohibit it. The debate with regard to whether or not an asheira is considered an opening is the subject of a dispute between Rabbi Yehuda, who permits using items from which it is prohibited to derive benefit for the sake of an eiruv, and the Rabbis, who prohibit making an eiruv with such items.

MISHNA: With regard to a ditch between two courtyards that is ten handbreadths deep and four handbreadths wide, it is considered a full-fledged partition, and the residents of the courtyard establish two eiruvin, one for each courtyard, but they may not establish one eiruv. Even if the ditch is filled with straw or hay, it is not regarded as sealed and is therefore not nullified. However, if the ditch is filled with dirt or pebbles, the residents establish one eiruv, but they may not establish two eiruvin, as the ditch is nullified and considered nonexistent.

If one placed a board four handbreadths wide across the ditch so that he could cross it, and similarly, if two balconies [gezuztraot] in two different courtyards are opposite one another, and one placed a board four handbreadths wide between them, the residents of the courtyards or balconies establish two eiruvin, and if they desire, they may establish one, as the board serves as an opening and a passageway between them. If the width of the plank is less than four handbreadths, the residents establish two eiruvin, but they may not establish one eiruv.

GEMARA: The Gemara wonders: Does hay not constitute a proper filling to seal the ditch? Didn’t we learn in the following mishna: With regard to a haystack ten handbreadths high that stands between two courtyards, the residents of the two courtyards establish two eiruvin, but they may not establish one eiruv. This indicates that hay can create a valid partition.

Abaye said that the matter should be understood as follows: With regard to a partition, everyone agrees that hay is a partition and that it divides between the courtyards as long as it is placed there. But with regard to filling the ditch so that it is considered sealed, one must distinguish between two cases: If one explicitly nullified the hay and decided to leave it there, it fills and seals the ditch; however, if he did not nullify it but intends to remove the hay from the ditch, it does not fill it, and the ditch is not considered sealed.

It is written in the mishna: If the ditch is filled with dirt or pebbles, it is considered sealed. The Gemara asks: Does this apply even if one did not specify his intention to leave it there? Didn’t we learn in a mishna with regard to the ritual impurity of a corpse: If there is a house that one filled with hay or pebbles, and he nullified the hay or pebbles and decided to leave them in the house, then the house (Rambam) is nullified and is no longer considered a house with partitions? Generally, a house containing a corpse is ritually impure on the inside but does not impart impurity to the surrounding area. However, in this case, the house is considered an enclosed grave that imparts ritual impurity to its surroundings.

And one can infer from the mishna: If he nullified the hay or pebbles, yes, the house is nullified and considered sealed.

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

Eruvin 78b examines minimum wall-groove dimensions for a valid ladder passageway and debates whether a tree can serve as an entryway between courtyards.