Reference for Shabbat 225:5
קשיא דר' יהודה אדרבי יהודה קשיא דרבנן אדרבנן
R. Judah's [views] are not self-contradictory: there it is not because looping may be mistaken for knotting, but [because] looping itself is [a form of] knotting.<span class="x" onmousemove="('comment',' In his view. ');"><sup>11</sup></span> R. Abba said in the name of R. Hiyya b. Ashi in Rab's name: A man may bring a cord from his house and tie it to a cow and [its] trough.<span class="x" onmousemove="('comment',' Without fear of subsequently leaving one end tied, in which case it becomes a permanent knot. ');"><sup>12</sup></span> R. Aha the Long, that is R. Aha b.Papa, refuted R. Abba: If a cord [is attached] to a trough, one may tie it to [his] cow; and if [attached] to a cow, one may tie it to a trough, provided however, that he does not bring a cord from his house and tie it to the cow and the trough? — There [the reference is to] an ordinary cord; here [we treat of] a weaver's cord.