Reference for Shabbat 292:12
<big><strong>גמ׳</strong></big> פשיטא מהו דתימא ניגזר משום אשוויי גומות קא משמע לן:
is forbidden. — What is the reason? R. Yemar of Difti<span class="x" onmousemove="('comment',' V. p. 35, n. 5. ');"><sup>19</sup></span> said: It is a preventive measure on account of [the making of] a pipe. R. Ashi said: It is a preventive measure lest one pluck it [from the tree]. Wherein do they differ? They differ where it is [already] plucked and [others too] are lying about.<span class="x" onmousemove="('comment',' There are plenty of leaves, so that there is no fear that one may pluck it, hence it is permitted (Wilna Gaon); but the first reason still holds good. R. Han. explains it thus: All agree that one may not make a funnel and insert it in the hole of a cask, but they differ where the leaf was already lying in the hole as a funnel from before the Sabbath. According to R. Yemar it is still forbidden to pour wine through it, lest he make a funnel, but according to R. Ashi it is permitted, since there is no fear of plucking a leaf from the tree. ');"><sup>20</sup></span>