Reference for Shabbat 17:2
אחרים אומרים אסקופה משמשת שתי רשויות בזמן שהפתח פתוח כלפנים פתח נעול כלחוץ
he is liable.<span class="x" onmousemove="('comment',' On Rashi's interpretation the difficulty is obvious: carrying an object via a place of non-liability is the same as transferring it from public to private ground by way of a threshold, which is a similar place, yet Raba rules that the former imposes liability, whereas the Baraitha states that the three are exempt. According to R. Han. and Tosaf. the difficulty appears to be this: when a person passes an object from one hand to another, his own body not moving, he is in a similar position to this man who stands on the threshold and takes the one and gives to the other, himself not moving, and its passing his stationary body in the former case is the same as when in the latter case it is laid down on the threshold; so, at least, one might argue. (Tosaf. a.l. s.v. [H] and in 'Er. 98a s.v. [H]) ');"><sup>2</sup></span>