If he placed it on a tree, higher than ten fists, his eruv is not valid; below ten fists, his eruv is valid. If he placed it in a ditch, even a hundred cubits deep, his eruv is valid. If he put it atop a reed or atop a pole, so long as it is uprooted and is stuck [into the ground], even if it is a hundred cubits high, his eruv is valid. If he placed it in a locker and lost the key, the eruv is valid. R’ Eliezer says: If he does not know that the key is in its place, the eruv is not valid.

If it rolled beyond the techum, or a heap fell on it, or it burned, or [it was] terumah which became contaminated — if it was still day, the eruv is invalid; if after dark, the eruv is valid. If it is in doubt — R’ Meir and R’ Yehudah say: He is caught in between. R’ Yose and R’ Shimon say: A doubtful eruv is valid. Said R’ Yose: Avtulmos attested in the name of five sages that a doubtful eruv is valid.

A person may attach a condition to his eruv and say, ‘‘If gentiles come from the east, my eruv is to the west; if from the west, my eruv is to the east; if they come from both directions, I shall go to the place I choose; if they do not come from either direc-tion, I am as my townspeople.’’ ‘‘If a scholar comes from the east, my eruv is to the east; from the west, my eruv is to the west; if one comes to here and [one comes] to there, I shall go to the place I choose; if to neither direction, I am as my townspeople.’’ R’ Yehudah says: If one of the scholars was his teacher, he must go to his teacher. But if both were his teachers, he may go to the place he chooses.

R’ Eliezer says: If Yom Tov adjoins the Sabbath either before it or after it — a person may make two eruvin and declare, ‘‘My eruv [for] the first is to the east and [for] the second to the west’‘; ‘‘[for] the first to the west and [for] the second to the east’’; ‘‘My eruv is [for] the first, but [for] the second I am as my townspeople’’; [or] ‘‘My eruv is [for] the second, but [for] the first I am as my townspeople.’’ But the Sages say: He makes an eruv to one direction or he makes no eruv at all; either he makes an eruv for both days or he makes no eruv at all. How should one proceed? He should take it on the first and stay with it until nightfall, then take it and go. On the second, he should stay with it until nightfall, then eat it. Thus he benefits in his walking [area], and he benefits from his eruv. If it was eaten on the first the eruv is valid for the first, but the eruv is not valid for the second. Said R’ Eliezer: [So] you agree with me that they are two [periods of] holiness!

R’ Yehudah says: [If before] Rosh Hashanah there was concern lest [Elul] be full, a person may make two eruvin and declare, ‘‘My eruv for the first is to the east, and for the second to the west’’; ‘‘For the first to the west, and for the second to the east’’; ‘‘My eruv is for the first, but for the second [I am] as my townspeople’’; [or] ‘‘My eruv is for the second, but for the first [I am] as my townspeople.’’ But the Sages did not agree with him.

Additionally, R’ Yehudah said: A person may stipulate a condition concerning a basket on the first day of Yom Tov and eat it on the second. And so also, an egg laid on the first may be eaten on the second. But the Sages did not agree with him.

R’ Dosa ben Harkinas says: He who leads the prayers on the Yom Tov of Rosh Hashanah says, ‘Fortify us, O HASHEM, our God, on this Rosh Chodesh, whether [it is] today or whether [it will be] tomorrow’’; and on the morrow he says,’’ . . . whether [it is] today or whether [it was] yesterday.’’ But the Sages did not agree with him.

One who was taken out by gentiles or by an evil spirit has only four cubits. If they brought him back, it is as if he never left. If they took him to another town, [or] if they put him in a fold or in a corral — Rabban Gamliel and R’ Elazar ben Azariah say: He may traverse its entirety. R’ Yehoshua and R’ Akiva say: He has only four cubits. It once happened that they arrived from Prandisin and their ship went out to sea. Rabban Gamliel and R’ Elazar ben Azariah traversed its entirety; R’ Yehoshua and R’ Akiva did not move out of four cubits, because they wished to be strict with themselves.

Once, they did not enter the harbor until night had fallen. They asked Rabban Gamliel: ‘‘May we disembark?’’ He answered them: ‘‘You are permitted, for I had been observing and we were within the techum before dark.’’

If one left with permission and they said to him: ‘‘The act has already been done,’’ he has two thousand cubits in every direction. If he was within the techum, it is as if he did not leave. [And] all those leaving to save [people] may return to their places.

One who sat down while on a journey, then stood up and saw that he was near a city, since it had not been his intention, he may not enter — [these are] the words of R’ Meir. R’ Yehudah says: He may enter. R’ Yehudah said: It once happened that R’ Tarfon entered without intent.