Related for Eruvin 195:17

חסורי מיחסרא והכי קתני במה דברים אמורים בכותל משופע אבל

seeing that it was taught: The writers of the scrolls of Scripture, tefillin or mezuzoth were not permitted to turn a skin<span class="x" onmousemove="('comment',' Lit., 'curtain',one of the sheets of parchment of which the large scroll is made up.');">⁴⁵</span> with the writing downwards,<span class="x" onmousemove="('comment',' Lit., 'on its face'; to protect it from dust.');">⁴⁶</span> but a cloth must be spread over it?<span class="x" onmousemove="('comment',' Sof. Ill, 14 and 16.');">⁴⁷</span> There<span class="x" onmousemove="('comment',' In the scribe's house.');">⁴⁸</span> this<span class="x" onmousemove="('comment',' To cover the writing with a cloth.');">⁴⁹</span> is possible whereas here<span class="x" onmousemove="('comment',' In the open, and where the exposed part of the scroll is rather large.');">⁵⁰</span> this is impossible; and if one were not to turn it over the holy writings would be exposed<span class="x" onmousemove="('comment',' Lit 'there is'.');">⁵¹</span> to much greater abuse. HE MUST TURN IT OVER WITH ITS WRITING DOWNWARDS. But, surely, it has not, has it, come to a rest?<span class="x" onmousemove="('comment',' In the public domain. Why then should it be forbidden to roll it back into the private domain seeing that such an act would not infringe even a shebuth?');">⁵²</span> - Raba replied: This is a case where the wall was slanting.<span class="x" onmousemove="('comment',' So that the end of the scroll inevitably comes to rest on the slope.');">⁵³</span> Said Abaye to him: You have explained our Mishnah as referring<span class="x" onmousemove="('comment',' Lit., 'in what did you place our Mishnah?'');">⁵⁴</span> to a slanting wall; read them the final clause: R'JUDAH RULED, EVEN IF IT WAS REMOVED FROM THE GROUND BY NO MORE THAN A THREAD'S THICKNESS, HE MAY ROLL IT BACK TO HIMSElf, but, surely,<span class="x" onmousemove="('comment',' Since the wall was slanting.');">⁵⁵</span> I may ask, has it not come to rest?<span class="x" onmousemove="('comment',' It must have done. Why, then, did R. Judah permit it to be rolled back?');">⁵⁶</span> - Some words are wanting, the proper reading<span class="x" onmousemove="('comment',' In our MISHNAH:');">⁵⁷</span> being as follows: This<span class="x" onmousemove="('comment',' The ruling that HE MUST TURN IT etc.');">⁵⁸</span> applies only to a slanting wall, but in the case

Kitzur Shulchan Arukh