Talmud - Eruvin 100a עירובין ק׳ א׳

This was prohibited because it is a dwelling that serves only the air, i.e., it is used only by someone guarding the fields or the like. It is not used as permanent living quarters, despite its partitions. And the rule with respect to any dwelling that serves only the air is that it is not permitted to carry in it if its area is more than two beit se’a. As it is not a proper place of residence, the Sages treated it as an enclosure.

The mishna states: If the roots of the tree are three handbreadths above the ground, one may not sit on them on Shabbat. It was stated that amora’im disagreed with regard to the roots of a tree that rise up and then bend and come down from above, from a height of three handbreadths to within three handbreadths of the ground. Rabba said: It is permitted to use them, and Rav Sheshet said: It is prohibited to use them.

The Gemara clarifies the rationale of each opinion. Rabba said that it is permitted to use them, as anything less than three handbreadths from the ground is considered as the ground. Rav Sheshet said: It is prohibited to use them; since they come from a prohibited source, they are prohibited. The section of the tree from which they grow is prohibited. Therefore, these roots should likewise be prohibited.

The Gemara proceeds to qualify the dispute: With regard to ascending and descending roots that resemble a rocky crag, those that rise upward are certainly prohibited according to all opinions; those that fall downward are permitted according to everyone. It is the roots that branch out to the sides that are the subject of the dispute between Rabba and Rav Sheshet. Rav Sheshet prohibits using them, while Rabba is lenient.

And likewise, Rabba and Rav Sheshet disagree about a tree that grows in a ditch that has elevated roots, some of which are concealed by the banks of the ditch. The amora’im dispute whether the roots concealed by the banks are considered part of the ground. And likewise, in the case of a tree that grows in a corner between two walls, they disagree as to whether the section between the walls is considered part of the ground.

The Gemara relates that Abaye had a certain palm tree that grew in his house and that projected through an opening in the roof. He came before Rav Yosef to ask him about it, and he permitted him to use the first three handbreadths of the palm tree above the roof, as the tree’s lower part is treated as though it were in the ground.

Rav Aḥa bar Taḥlifa said to Abaye: He who permitted it to you, permitted it to you in accordance with the opinion of Rabba, who maintains that a section of a tree concealed from view in at least two directions is considered as though it were underground. Consequently, the first three handbreadths above that section may be used on Shabbat, as they have the status of the ground.

The Gemara expresses surprise: This is obvious. What novel element is Rav Aḥa bar Taḥlifa teaching us? The Gemara answers: It is necessary, lest you say that in this case it should be permitted even according to Rav Sheshet, as the house is considered full, i.e., it is as though it were filled with earth, and this would mean it is permitted to use the section less than three handbreadths from the roof. Rav Aḥa bar Taḥlifa therefore teaches us that Rav Sheshet is stringent even in this case.

The Gemara attempts to adduce proof from the mishna, in which we learned: If the roots of the tree are three handbreadths above the ground, one may not sit on them. What are the circumstances of this case? If the situation is that the roots do not bend over again, this is obvious, as anything higher than three handbreadths is part of the tree. Rather, doesn’t it mean that one may not sit on them even though they bend back downward to within three handbreadths of the ground? The mishna apparently indicates that if parts of the roots are more than three handbreadths above the ground, it is prohibited to use them along the rest of their entire length, as maintained by Rav Sheshet, contrary to Rabba.

The Gemara rejects this contention: No, actually the mishna is referring to a case where they do not bend back downward, and the tanna comes to teach us the following: Although on one side of the tree the roots are level with the ground, nevertheless, it is prohibited to sit on them, as the roots on the other sides are more than three handbreadths above the ground.

The Sages taught in a baraita: With regard to roots of a tree that are three handbreadths above the ground, or if there is a hollow space beneath them of three handbreadths, although on one side of the tree the roots are level with the ground, one may not sit on them because of the following rule: One may not climb a tree, nor may one hang from a tree by one’s hands, nor may one even lean against a tree on Shabbat.

And similarly, one may not climb a tree on Friday while it is still day and sit there the entire day of Shabbat. This constitutes the use of the tree itself, not merely climbing it, and it is therefore prohibited. This halakha applies both to a tree and to all animals; one may not climb upon them, hang from them, or lean against them. However, the prohibition is not due to the effort involved in climbing, as is evident from the case of a cistern, ditch, cave, or a fence. One may climb up and climb down them, even if they are a hundred cubits deep.

The Gemara comments: It was taught in one baraita: If one climbed up a tree, he is permitted to climb down; and it was taught in one other baraita that he is prohibited to climb down. The Gemara resolves this apparent contradiction: This is not difficult. Here, where it is permitted to descend, one climbed up on Friday, while it was still day; there, where it is prohibited to descend, one climbed up on Shabbat after nightfall.

And if you wish, say instead that both baraitot are referring to a case where one climbed up the tree after nightfall. But even so, it is not difficult: Here, it is permitted to descend, as one climbed up the tree unwittingly; there, it is prohibited to descend, as the baraita is dealing with one who climbed intentionally.

And if you wish, say instead that both baraitot are referring to a case where one climbed up unwittingly, and they disagree about whether or not the Sages penalized an unwitting offender due to an intentional offender. One Sage, who ruled that it is prohibited to descend, maintains that they penalized an unwitting sinner to prevent others from climbing up on purpose and descending. Therefore, one may not come down even if he ascended by mistake. And one Sage, who ruled that it is permitted, maintains that they did not penalize the unwitting sinner in this manner.

Rav Huna, son of Rav Yehoshua, said: This dispute between the two baraitot is parallel to the dispute of the tanna’im, who disagreed with regard to a different matter. The blood of certain sacrifices, e.g., the firstborn and tithe offerings, is sprinkled once on the altar, while the blood of other sacrifices, e.g., burnt-offerings, is sprinkled four times. They require two sprinklings that are four, i.e., two sprinklings on opposite corners, so that the blood falls on all four sides. If the blood of sacrifices that require only one sprinkling becomes intermingled with the blood of other sacrifices that require only one sprinkling, the mixture will be sprinkled once. Likewise, if the blood of sacrifices that require four sprinklings becomes intermingled with the blood of other sacrifices that require four sprinklings, the mixture will be sprinkled four times.

If, however, the blood of a sacrifice that requires four sprinklings becomes intermingled with the blood of a sacrifice that requires only one sprinkling, the tanna’im disagree: Rabbi Eliezer says: The mixture of blood is sprinkled four times. And Rabbi Yehoshua says: It is sprinkled once, and this suffices for the atonement of the sacrifice.

Rabbi Eliezer said to Rabbi Yehoshua: If one sprinkles the blood only once, he transgresses the prohibition “you shall not diminish,” which prohibits the omission of any elements of the performance of a mitzva, as he has not sprinkled the blood of the burnt-offering in the proper manner. Rabbi Yehoshua said to Rabbi Eliezer: According to your ruling, that one must sprinkle the blood four times, he transgresses the prohibition: Do not add (Deuteronomy 13:1), which prohibits the addition of elements to a mitzva, as he sprinkles the blood of the firstborn animal more times than necessary.

Rabbi Eliezer said to Rabbi Yehoshua: They said the prohibition against adding to the mitzvot only where the blood stands by itself, not when it is part of a mixture. Rabbi Yehoshua said to Rabbi Eliezer: Likewise, the prohibition: Do not diminish, was stated only in a case where the blood stands by itself.

And Rabbi Yehoshua further said in defense of his position: When you sprinkle four times, you have transgressed the prohibition: Do not add, with regard to one of the sacrifices, and you also performed an action with your own hand, i.e., you transgress the Torah’s command by means of a positive act. By contrast, when you do not sprinkle four times, even if you have transgressed the prohibition: Do not diminish, you did not perform the action with your own hand. If one is forced to deviate from the commands of the Torah, it is better to do so in a passive manner.

Rav Huna, son of Rav Yehoshua, sought to argue the following: According to Rabbi Eliezer, who said there, with regard to sacrifices, that if both alternatives involve the violation of a prohibition it is preferable to stand and take action, i.e., perform a positive action, here too, one should climb down from the tree, as it is better to perform a single positive transgression by climbing down rather than commit a passive transgression throughout the entire Shabbat by remaining on the tree. By contrast, according to Rabbi Yehoshua, who said with regard to sacrifices that it is preferable to sit and not take action, here too, one should not descend from the tree.

The Gemara refutes this comparison: Perhaps that is not the case, as the two halakhot are not identical. Rabbi Eliezer might have stated his opinion that it is preferable to stand and take action only in the case dealt with there, where one performs a mitzva with respect to the additional sprinklings of the burnt-offering. However, here, where one performs no mitzva whatsoever by descending, indeed, he should not descend.

Alternatively, the comparison can be rejected in a different fashion: Rabbi Yehoshua may have stated his opinion that it is preferable to sit and not take action only in the case dealt with there,

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

Eruvin 100a examines Shabbat carrying laws for field shelters and debates among amoraim over sitting or using tree roots near the ground.