Reference for Shabbat 198:5

מחט נמי א"א דלא מדליא פורתא דאית ליה מורשא א"נ דרמיא בחריצה

or perhaps since it comes from a place of non-liability<span class="x" onmousemove="('comment',' V. supra 6a. The object must sail through the air above ten handbreadths in order for it to alight on the top of column of that height. ');">⁴</span>

Jastrow

Jastrow