Siman - Eruvin Daf 52

• Rebbe Yose be’Rebbe Yehuda’s leniency

It was taught in a Baraisa, מי שיש לו שני בתים וביניהן שני תחומי שבת – one who has two homes, separated by a distance equal to two techumin, meaning four thousand amos, כיון שהחזיק בדרך – as soon as he takes to the road, קנה עירוב – he acquires an eruv. Rebbe Yose Be’Rebbe Yehuda said even more than this, that even if his friend met him as he was setting out to travel and said to him, “Spend the night here because the weather is too hot or cold for traveling,” and he followed his advice, למחר משכים והולך – the next day, which is Shabbos, he may rise and travel to the next city.

There is a machlokes regarding what was Rebbe Yose Be’Rebbe Yehuda’s additional leniency.

Rabbah said that everybody agrees that he needs to verbally declare that his desired residence is in the next city, כי פליגי להחזיק – they disagree only whether he actually needs to set out for the second city. Rebbe Yose Be’Rebbe Yehudah says he does not, and he only needs to plan to do so.

Rav Yosef said that everybody agrees that he needs to take to the road, כי פליגי לומר – they disagree only if he needs to verbally declare that his desired residence is in the second city .

• Going outside the techum b’meizid

The next Mishnah states, מי שיצא חוץ לתחום, - Someone who exited the techum, which Rashi explains to mean with daas, b’meizid, and not for the purpose of a mitzvah, אפילו אמה אחת – even one amah past the boundary, לא יכנס – may not enter the techum. Rebbe Eliezer says he may reenter if he went two amos, but not if he went three amos. Rashi explains that according to Rebbe Eliezer, since a person is considered in the middle of his dalet amos, with two amos all around him, the two amos overlap with his original techum, as he holds of הבלעת תחומין. The Tanna Kamma holds a meizid cannot take advantage of הבלעת תחומין – of overlapping techumin.

• אין המשוחות ממצין את המדות

The last Mishnah in the perek states, מי שהחשיך חוץ לתחום – one who was outside of the techum when it became dark, even by only one amah, may not enter the techum. Rebbe Shimon says that he may enter back into the techum even if he was fifteen amos past the techum, שאין המשוחות ממצין את המדות – for the surveyors who place markers to delineate the city’s techum do not place them exactly at two thousand amos, מפני הטועין – because of those that err, meaning people who wander slightly beyond the markers.

Rashi gives two explanations regarding the fifteen amos. The first pshat is that fifteen amos is לאו דוקא. Rather it is an approximation. The second pshat is based on the fact that the surveyors measure the techum with ropes measuring 50 amos. Since this necessitates measuring 40 times, and one tefach and half a fingerbreadth of the rope is held by each surveyor at the ends, a total of fifteen amos is lost when they measure the techum.