Reference for Eruvin 50:3

מתקיף לה רב יוסף וכי אויר המותר לו אוסרו

towards a courtyard [the movement of objects within it] is forbidden. What is the reason? Because the space of the courtyard increases its extent.<span class="x" onmousemove="('comment',' Above the permitted size, the principle, 'The edge of the ceiling etc.' being inapplicable in this case.');">⁷</span>

Jastrow

Jastrow

Jastrow