One who slept while on a journey and did not know that it had become dark has two thousand cubits in every direction — [these are] the words of R’ Yochanan ben Nuri. But the Sages say: He has only four cubits. R’ Eliezer says: And he is in their midst. R’ Yehudah says: He may go in any direction he wishes. Yet R’ Yehudah agrees that once he chooses for himself, he cannot retract.

If there were two, some of the cubits of one overlapping the cubits of the other, they may bring [their food] and eat in the middle, provided that one does not carry from his into his friend’s. If there were three and the middle one’s [area] was overlapped by the other two, he is permitted with them, and they are permitted with him; but the outer two are forbidden with each other. Said R’ Shimon: To what is this comparable? To three courtyards which open one into the other and which open into the public domain. If the two made an eruv with the middle one, it is permitted to them, and they are permitted to it; but the two outer ones are forbidden one to another.

One who was traveling as darkness approached, and he knew [of] a tree or a fence, and said, ‘‘My Sabbath dwelling place is beneath it,’’ has said nothing. [If, however, he said,] ‘‘My Sabbath dwelling place is at its trunk,’’ he may walk from his present location to the trunk two thousand cubits, and from the trunk to his house two thousand cubits. Thus, he may go four thousand cubits after dark.

If he does not know, or he is not conversant with the law, and he said, ‘‘My Sabbath dwelling place is at my location,’’ his location acquires two thousand cubits for him in every direction. In a circle — [these are] the words of R’ Chanina ben Antignos. But the Sages say: In a square, like a square board, so that he may gain the corners.

This is what they have said: ‘‘The poor man may make an eruv with his feet.’’ Said R’ Meir: We can apply this only to a poor man. R’ Yehudah says: Both a poor man and a rich man; they did not say, ‘‘We may make an eruv with bread,’’ except to make it easier for the rich man, so that he not go out and make an eruv with his feet.

One who set out for a town for which they may make an eruv, but his friend turned him back, he may go, but all the townspeople are prohibited — [these are] the words of R’ Yehudah. R’ Meir says: Whoever is able to make an eruv and does not, he is caught in between.

One who went out of the techum, even one cubit, may not return. R’ Eliezer says: Two cubits, he may return; three cubits, he may not return. One who was overtaken by darkness outside the techum, even one cubit, may not enter. R’ Shimon says: Even fifteen cubits, he may enter; for the surveyors do not give the full measure, because of those who err.

How does one extend the towns? A house is recessed [or] a house protrudes, a tower is recessed [or] a tower protrudes, there were ruins ten fists high, or bridges or mausoleums in which there is a dwelling, they extend the boundary opposite them, and they make it as a square tablet, so that one may gain the corners.

We grant a karpeif to a town — [these are] the words of R’ Meir. But the Sages say: They did not say [the rule of] karpeif, except between two towns; if this one has seventy cubits and a fraction and that one has seventy cubits and a fraction, a karpeif is granted to the two of them to become as one.

Similarly, three villages forming a triangle, if there are one hundred forty-one and a third [cubits] between the two outer ones, the middle one causes all three of them to become as one.

We may not measure except with a fifty cubit rope, neither shorter nor longer. One may not measure except [with the rope] opposite his heart. If he was measuring and reached a valley or a mound, he should span it and return to his measuring; if he reached a mountain, he should span it and return to his measuring; provided he does not go out of the techum. If he is unable to span it — regarding this R’ Dostai bar R’ Yannai stated in R’ Meir’s name: I have heard that we pierce mountains.

We may not [accept] measure[ments] except from an expert. If he extended [the techum] at one point and shortened it at another, the extended [techum] is followed. If one extended [it] while another shortened [it], the one who extended [it] is followed. Even a male slave, even a female slave is believed to say, ‘Until here is the Sabbath techum.’’ For the Sages did not state this law to be stringent but rather to be lenient.