Study Eruvin folio 78B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Rav Yosef further asked: If the ladder resting against the wall was less than 4 handbreadths wide, and one dug out grooves in the wall as extensions of the rungs of the ladder to complete the measure, how high must this hollowed-out section be to consider the ladder a valid passageway between the tw
Rav Yosef said to him: If there was no ladder, and one dug out the entire ladder in the wall, so that all the steps are grooves in the wall, how much must he hollow out? Rabba said to him: Those steps must reach the full height of the wall. Rav Yosef asked: And what is the difference in this case
Rav Yosef raised a dilemma before Rabba: If one designated a tree as a ladder, what is the halakha? Given that it is prohibited to climb a tree on Shabbat, if a tree stands next to a wall and it is easy to climb, is it considered with regard to the halakhot of Shabbat as an opening in the wall that
Let the dilemma be raised according to the opinion of R' Yehuda HaNasi, who maintains that a joining of Shabbat boundaries [eiruv teḥumin] placed in a tree is valid; and let the dilemma be raised according to the opinion of the Rabbis, who disagree.
The Talmud elaborates: Let the dilemma be raised according to the previously stated opinion of R' Yehuda HaNasi. R' Yehuda HaNasi only stated there that with regard to anything that is prohibited on Shabbat due to a rabbinic decree [shevut], the rabbis did not prohibit it during twilight. Therefore