Talmud - Eruvin 79a עירובין ע״ט א׳

However, if he did not nullify it, no, the house retains the status of a house, although it is filled with hay. Rav Huna said: Who is the tanna who taught tractate Oholot? It is Rabbi Yosei, and the tanna of the mishna does not accept his opinion.

The Gemara asks: If that mishna is in accordance with the opinion of Rabbi Yosei, there is a difficulty, since we heard him say the opposite, as it was taught in the Tosefta that Rabbi Yosei says: In a case where there is a house full of hay and the owner does not intend to remove, it is considered as though it were filled with indeterminate dirt, and it is therefore nullified. However, if the house was full of dirt that he intends to remove, it is considered as though it were filled with indeterminate hay, and it is therefore not nullified. Apparently, the decisive factor for Rabbi Yosei is not the specific material in the house, but whether or not the owner intends to remove it.

Rather, Rav Asi said: Who is the tanna who taught tractate Eiruvin? It is Rabbi Yosei, who does not accept the opinion of the tanna of tractate Oholot.

Rav Huna, son of Rav Yehoshua, said: Are you raising a contradiction between the halakhot of ritual impurity and the halakhot of Shabbat? These two areas of halakha cannot be compared. Leave aside the prohibition of Shabbat. With regard to Shabbat, a person nullifies even a pouch full of money. The pouch may not be moved on Shabbat and is therefore considered fixed in place. However, hay, which may be moved even on Shabbat, is not considered to be fixed in the ditch. With regard to ritual impurity, by contrast, the nullification must be permanent.

Rav Ashi said: And are you raising a contradiction between the halakha that governs a house and that which governs a ditch? Granted in the case of a ditch, it typically stands to be permanently filled. As there is no doubt that one’s intention is to fill the ditch, the assumption is that anything placed inside a ditch will remain there. However, does a house stand to be permanently filled? Of course it does not. Presumably, the hay and dirt will be removed. Consequently, additional proof is necessary in order to conclude that the owner of the house intends to seal it permanently.

The mishna states: If one placed a plank that is four handbreadths wide across a ditch that separates two courtyards, the plank is considered an entrance. Rava said: They taught this halakha only in a case where one placed the plank along the width of the ditch. But if one positioned a plank along its length, even if the plank is of minimum width, it is also considered an entrance and reduces the ditch, as he reduced the opening to less than four handbreadths. The ditch was originally only four handbreadths wide. Therefore, if one places a plank of any width along its length, it becomes less than four handbreadths wide and no longer constitutes a partition.

The mishna continues: And similarly, if two balconies are opposite each other, and one placed a plank four handbreadths wide between them, the residents of the two courtyards may establish a single eiruv, as the plank is considered an entrance from one courtyard to the other. Rava said: That which you said: If the two balconies are opposite each other, yes, carrying between them is permitted by means of a plank; by inference, if they are not opposite each other, no, carrying is not permitted in this manner, and in a case where one balcony is above the other as well, it is prohibited, as it is not an entrance because it is too dangerous to walk from one to the other by means of the plank. We said the prohibition in these cases only where there is a disparity of at least three handbreadths between this balcony and that balcony. However, if there is a difference of less than three handbreadths between this balcony and that balcony, it is considered a single crooked balcony. Two balconies separated by a gap of less than three handbreadths are considered joined, based on the principle of lavud.

MISHNA: With regard to a haystack that is positioned between two courtyards and is ten handbreadths high, it has the status of a partition, and therefore the residents of the courtyards may establish two eiruvin, and they may not establish one eiruv. These, the inhabitants of one courtyard, may feed their animals from here, from one side of the haystack, and those, the inhabitants of the other courtyard, may feed their animals from there, from the other side of the haystack. There is no concern that the haystack might become too small to serve as a partition. If the height of the hay was reduced to less than ten handbreadths across its entire length, its legal status is no longer that of a partition. Consequently, the residents of both courtyards establish one eiruv, and they do not establish two eiruvin.

GEMARA: With regard to the mishna’s statement that the inhabitants of the two courtyards are permitted to place their animals next to the haystack and feed them, Rav Huna said: And this is the halakha provided that one does not actually put hay into his basket and feed his animals. In that case, there is concern that one might inadvertently reduce the height of the partition to less than ten handbreadths, which would constitute a breach between the courtyards and invalidate both eiruvin.

The Gemara asks: And if the actual handling of the hay is prohibited, is it permitted to stand one’s animal next to the haystack and let it eat? Didn’t Rav Huna say that Rabbi Ḥanina said: A person may stand his animal on a patch of grass on Shabbat, as he will certainly be careful not to pull out grass for the animal, due to the severity of the Torah prohibition involved. However, a person may not stand his animal on set-aside items on Shabbat. As the prohibition of set-aside is rabbinic in origin, he might forget and move the set-aside objects himself. The same reasoning should apply in the case of the haystack. If it is prohibited by rabbinic decree to remove hay from the stack manually, it should likewise be prohibited to position one’s animal alongside the stack.

The Gemara answers: The mishna is not referring to a case where one directly brings the animal and places it alongside the haystack. Rather, it is dealing with a situation where one stands in front of the animal so that it cannot go elsewhere, and it goes and eats from the haystack of its own accord. In that case, the rabbinic decree does not apply.

The Gemara asks a question with regard to Rav Huna’s statement itself: And may one not put hay into his basket and feed his animal? Wasn’t it taught in a baraita: In the case of a house that is positioned between two courtyards and the residents filled it with hay, they establish two eiruvin, but they do not establish one eiruv, as the hay is considered a partition that divides the house. The resident of this courtyard puts hay into his basket and feeds his animal, and the resident of that courtyard puts hay into his basket and feeds his animal. If the hay was reduced to a height less than ten handbreadths, it is prohibited for residents of both to carry in their respective courtyards.

How, then, does the resident of one of the courtyards act if he seeks to permit use of the other courtyard to its resident? He locks his house and renounces his right to carry in the courtyard in favor of the other person. Consequently, it is prohibited for him to carry from his house into the courtyard, and it is permitted for the other resident to do so.

And you say likewise with regard to a pit [gov] of hay that is positioned between two Shabbat limits. The residents of each area may feed their animals from the common hay, as there is no concern lest the animals go beyond the limit. In any case, the baraita teaches: The resident of this courtyard puts hay into his basket and feeds his animal, and the resident of that courtyard puts hay into his basket and feeds his animal. This halakha poses a difficulty to Rav Huna’s opinion.

The Gemara answers: We can say that in the case of a house, since it has walls and a ceiling, when the height of the haystack is reduced the matter is conspicuous. The height disparity between the haystack and the ceiling is obvious. Consequently, when the haystack is reduced to less than ten handbreadths, people will stop carrying in the courtyard. Here, however, with regard to the hay in the pit, the difference in height is not conspicuous. The height of the hay in the pit could become diminished to the extent that the partition is nullified without anyone noticing.

It is stated in the baraita: If the height of the hay was reduced to less than ten handbreadths it is prohibited to carry in both courtyards. The Gemara infers from the phrasing of the baraita: If the hay was at least ten handbreadths high, it is permitted to carry there, even though the ceiling is much higher than the hay. Conclude from it that the legal status of ten-handbreadth partitions that do not reach the ceiling is that of standard partitions, which was the subject of a dispute elsewhere. Apparently, this baraita proves that they have the status of partitions in all respects.

Abaye said: Here, we are dealing with the case of a house that is slightly less than thirteen handbreadths high and the hay is ten handbreadths high. The haystack is less than three handbreadths from the ceiling, and based on the principle of lavud, they are considered joined as though the partitions reach the ceiling.

And Rav Huna, son of Rav Yehoshua, said: Even if you say that the baraita is dealing with a house ten handbreadths high,

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

Eruvin 79a explores whether a hay-filled house or ditch retains its status, contrasting Shabbat boundary rules with laws of ritual impurity.