Yerushalmi Eruvin 4:10 ירושלמי עירובין ד׳:י׳

MISHNAH: If somebody left the Sabbath domain for even one cubit he may not reenter. Rebbi Simeon says, Rebbi Eleazar says, for two he may re-enter, three he may not re-enter. If somebody was outside the Sabbath domain at nightfall for even one cubit he may not enter. Rebbi Simeon says, even fifteen cubits he may enter since the rope-spanners do not exhaust the measure because of errors²⁰This introduces the first topic of the next Chapter, the determination of the Sabbath boundaries of a town. Since the exact determination of a linear distance would require multiple measurements, the officials charged with marking the borders will intentionally err on the side of caution. In case of need one may assume that the official measurement is 0.75% short of the true value..

HALAKHAH: Paragraph. “If somebody left the Sabbath domain,” etc. Rebbi Aḥa in the name of Rebbi Ḥinena and Rav Ḥasdai both are saying, he said only “two”. Therefore could he enter with two and a little bit? Since this is Rebbi Eleazar’s, as Rebbi Eleazar said, “for two he may re-enter, three he may not re-enter.” Rebbi Yose told him, one says at the end, “three he may not re-enter,” therefore three minus a little bit he may re-enter⁹¹The statement of R. Eleazar in Mishnah 12 does not permit to decide what happens if a person left the Sabbath domain for more than two but less than three cubits.. They wanted to say, what Rebbi Eleazar said is about one who left, therefore not about one who stayed overnight⁹²Since R. Eleazar speaks only about a person who left his Sabbath domain, not a traveller whose 2’000 (or 4’000) cubits end just two cubits short of the Sabbath domain of the next town. Since practice follows the Sages, these problems do not have to be resolved.. It was found stated, one is like the other. They wanted to say, what Rebbi Simeon said is about one who stayed overnight, therefore not about one who left. It was found stated, one is like the other.