Talmud - Eruvin 48a עירובין מ״ח א׳

an iron partition to divide it into two separate areas, so that the residents of both places may draw water from it. Rabbi Yosei, son of Rabbi Ḥanina, would laugh at this teaching, as he deemed it unnecessary.

The Gemara asks: Why did Rabbi Yosei, son of Rabbi Ḥanina, laugh? If you say that it is because Rabbi Ḥiyya taught the baraita stringently, in accordance with the opinion of Rabbi Yoḥanan ben Nuri, saying that ownerless objects acquire a place of residence, and Rabbi Yosei, son of Rabbi Ḥanina holds leniently, in accordance with the opinion of the Rabbis and says that those objects do not acquire residence, this is difficult. Just because he holds leniently, does he laugh at one who teaches stringently?

Rather, he must have laughed for a different reason, as it was taught in a baraita: Flowing rivers and streaming springs are like the feet of all people, as the water did not acquire residence in any particular spot. Consequently, one who draws water from rivers and springs may carry it wherever he is permitted to walk, even if it had previously been located outside his Shabbat limit. According to Rabbi Yosei, son of Rabbi Ḥanina, the same halakha should apply to the water in the ditch.

The Gemara rejects this argument: No proof can be brought from this ruling concerning rivers and springs, as perhaps we are dealing here with a ditch of still, collected water that belongs exclusively to the residents of that particular place.

Rather, Rabbi Yosei, son of Rabbi Ḥanina, must have laughed for a different reason, because Rabbi Ḥiyya taught in his baraita that the ditch requires an iron partition to divide it into two separate sections. Rabbi Yosei, son of Rabbi Ḥanina, argued: Why is a partition of reeds different, that we should say it is not effective in that case? Apparently, it is because water enters it and passes from one limit to the other. But this is difficult, as even in the case of a partition of iron, water enters it and passes from one limit to another, as it cannot be hermetically sealed. If so, what does the iron accomplish that the reeds do not accomplish?

The Gemara raises a difficulty: Perhaps the baraita is saying as follows: A water-filled ditch that lies between two Shabbat limits requires an iron partition to divide it into two separate sections. But there is no remedy, because it is impossible to hermetically seal a partition of that kind, and therefore its water may not be used.

Rather, you must say that Rabbi Yosei, son of Rabbi Ḥanina, laughed at Rabbi Ḥiyya’s teaching for a different reason, because the Sages were lenient with regard to water. The Rabbis said that a minimal partition suffices in the case of water. Consequently, there should be no need for an iron partition.

This is similar to the case involving Rabbi Tavla, as Rabbi Tavla asked of Rav: Does a suspended partition, i.e., a partition that is suspended and does not reach the ground, permit carrying in a ruin? Do we say that the remnants of the walls that are suspended in the air are considered as though they descend to the ground and close off the area, so that it is regarded as a private domain?

Rav said to him: A suspended partition of this kind permits carrying only in the case of water, as the Sages were lenient with regard to water. Just as the Sages were lenient about water with respect to a suspended partition, so too they should be lenient here and not require an iron partition; rather, a minimal partition should suffice, even one made of reeds.

The mishna taught: And the Rabbis say that if a person is sleeping at the onset of Shabbat and has no intention of acquiring residence in his location, he has only four cubits, whereas Rabbi Yehuda says he can walk four cubits in any direction he chooses. The Gemara asks: What is the dispute? The opinion of Rabbi Yehuda is the same as that of the first tanna, i.e., the Rabbis.

Rava said: There is a practical difference between them, as the Rabbis permit him to carry in an area of eight by eight cubits. Rabbi Yehuda maintains that he has only four cubits, in the direction of his choosing, whereas according to the Rabbis he has four cubits in every direction, which totals an area of eight by eight cubits. That was also taught explicitly in a baraita: He has eight by eight cubits; this is the statement of Rabbi Meir, which is the opinion of the Rabbis of the mishna.

And Rava further stated: This dispute between Rabbi Meir and Rabbi Yehuda relates only to walking, but as for carrying objects, all agree that to carry them four cubits is indeed permitted; but to carry them more than that is not.

The Gemara inquires about the basis of this law: These four cubits within which a person is always permitted to walk on Shabbat, where are they written in the Torah?

The Gemara answers: As it was taught in a baraita: The verse “Remain every man in his place; let no man go out of his place on the seventh day” (Exodus 16:29), means one must restrict his movement to an area equal to his place. And how much is the area of his place? A person’s body typically measures three cubits, and an additional cubit is needed in order to allow him to spread out his hands and feet, this is the statement of Rabbi Meir. Rabbi Yehuda says: A person’s body measures three cubits, and an additional cubit is needed in order to allow him to pick up an object from under his feet and place it under his head, meaning, to give him room to maneuver.

The Gemara asks: What is the practical difference between them? The Gemara answers: There is a practical difference between them in that Rabbi Yehuda provides him with exactly four cubits but no more; whereas Rabbi Meir maintains that we do not restrict him in this manner, but rather he is provided with expansive cubits, i.e., enough room to spread out his hands and feet, which measures slightly more than four cubits.

Rav Mesharshiya said to his son: When you come before Rav Pappa, inquire of him as follows: The four cubits [ammot] mentioned here, do we grant them to each person measured according to his own forearm [amma], i.e., the distance from his elbow to the tip of his index finger, or do we grant them measured according to the cubit [amma] used for consecrated property, i.e., a standard cubit of six medium handbreadths for everyone?

If he said to you that we provide him four cubits measured according to the standard cubit used for consecrated property, what will be with regard to Og, king of the Bashan, who is much larger than this? And if he said to you that we provide him four cubits measured according to his own forearm, say to him: Why was this halakha not taught together with the other matters whose measures are determined by the specific measure of the person involved, in the mishna that teaches: These are matters with regard to which they stated measures all in accordance with the specific measure of the person involved. This means that the measures are not fixed, but rather change in accordance with the person in question. If the four cubits are measured according to each person’s forearm, this law should have been included in the mishna.

When Rav Mesharshiya’s son came before Rav Pappa, the latter said to him: Were we to be so precise, we would not be able to learn anything at all, as we would be too busy answering such questions.

In fact, we grant him four cubits measured according to his own forearm. And as for that which was difficult for you, why was this law not taught in the mishna that teaches: These are matters with regard to which they stated measures all in accordance with the specific measure of the person involved? It is because this law is not absolutely clear-cut. It occasionally must be adjusted, since there may be a person whose limbs are small in relation to his body. With regard to such a person, we do not measure four cubits according to the size of his own forearm, but rather by the standard cubits used for consecrated property.

The mishna taught: If there were two people positioned in a way that part of the four cubits of the one were subsumed within the four cubits of the other, they each may bring food and eat together in the shared area in the middle. Rabbi Shimon likened this case to that of three courtyards that open one into another, where the two outer courtyards established an eiruv with the middle one. The Gemara asks: Why does Rabbi Shimon need to offer an analogy and say: To what may this be likened, and thus connect our case to a different issue?

The Gemara explains: This is what Rabbi Shimon said to the Rabbis: After all, to what is this similar? To three courtyards that open into one another, and that also open into a public domain. What is different there that you disagree with me and say that it is prohibited to carry from any one courtyard to any other, and what is different here that you do not disagree with me?

And how do the Rabbis reply? There the residents of the courtyards are numerous, and some might come to carry objects in a place where it is prohibited to do so; whereas here the residents are not numerous, and a mere three people can warn each other against Shabbat desecration.

The mishna taught: If the residents of the two outer courtyards established an eiruv with the middle one, it is permitted to carry from the middle one to the two outer ones, and it is permitted to carry from the two outer ones to the middle one. And it is prohibited to carry from one of the two outer courtyards to the other, as they did not establish a joint eiruv. The Gemara asks: Why is it prohibited? Since the residents of the outer courtyards established an eiruv with the middle one, they are as one, and consequently, they should all be permitted with one another.

Rav Yehuda said: The mishna is referring to a case where the two outer courtyards did not place their eiruv in the middle courtyard; rather, to a case where the residents of the middle courtyard placed its first eiruv in this courtyard and its second eiruv in that courtyard, so that the eiruv of each of the other courtyards is not in the middle courtyard.

And Rav Sheshet said: Even if you say that the residents of each of the outer courtyards placed their eiruv in the middle courtyard, they are still not considered a single courtyard, as we are dealing with a case where they placed each eiruv

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

Eruvin 48a examines whether a shared ditch straddling two Shabbat boundaries needs a physical partition, debating iron versus reed dividers and the status of flowing water.