Commentary for Bava Kamma 52:11
ואמר רבה זרק תינוק מראש הגג ובא אחר וקבלו בסייף פלוגתא דר' יהודה בן בתירא ורבנן דתניא הכוהו עשרה בני אדם בעשרה מקלות בין בבת אחת בין בזה אחר זה כולן
from the top of a roof and another one coming and breaking it with a stick [before it fell upon the ground where it would in any case have been broken], the latter is under no liability to pay; the reason being that it was only a utensil which was already certain to be broken that was broken by him. Rabbah further said: In the case of a man throwing a utensil<span class="x" onmousemove="('comment',' Belonging to another. ');"><sup>31</sup></span> from the top of the roof while there were underneath mattresses and cushions which were meanwhile removed by another person, or even if he [who had thrown it] removed them himself, there is exemption; the reason being that at the time of the throwing [of the utensil] his agency had been void of any harmful effect.<span class="x" onmousemove="('comment',' Lit., 'he had let his arrow off', it had spent its force; i.e., when the act of throwing took place it was by no means calculated to do any damage. ');"><sup>32</sup></span> Rabbah again said: In the case of one throwing a child from the top of the roof and somebody else meanwhile appearing and catching it on the edge of his sword, there is a difference of opinion between R. Judah b. Bathyra and the Rabbis.<span class="x" onmousemove="('comment',' According to R. Judah, the latter who caught it on the edge of his sword will be guilty of murder, but according to the Rabbis, no one is guilty of it. ');"><sup>33</sup></span> For it was taught: In the case of ten persons beating one [to death] with ten sticks, whether simultaneously or consecutively, none of them