Reference for Zevachim 47:7

רבה זוטי בעי לה הכי בעי רבי אמי נעקרה האבן ועמד במקומה מהו

R'Ammi asked: What if a [paving] stone become loosened and he stood on it?<span class="x" onmousemove="('comment',' So that it moves about.');">⁶</span> If it is not his intention to fit it [in the pavement] there is question, for it certainly interposes;<span class="x" onmousemove="('comment',' It is not accounted part of the pavement.');">⁷</span>

Jastrow