Reference for Bava Metzia 189:25
אלא תנא מילתא
We learnt: IF A MAN BORROWS A COW AND BORROWS ITS OWNER WITH IT, OR BORROWS A COW<span class="x" onmousemove="('comment',' [This phrase does not occur in our Mishnah but is introduced by the Talmud in the text to exclude the possible assumption that the reference here is to the hiring of the cow. V. Strashun, a.l.] ');"><sup>24</sup></span> AND HIRES THE OWNER WITH IT, OR IF HE FIRST BORROWS OR HIRES THE OWNER AND THEN BORROWS THE COW, AND IT DIES, HE IS NOT RESPONSIBLE. But a gratuitous bailee is not mentioned!<span class="x" onmousemove="('comment',' Which proves that the service of the owner does not free him where he would otherwise be responsible, viz., in the case of culpable negligence, thus refuting the contrary view. ');"><sup>25</sup></span> — But even on your reasoning, is then a paid bailee mentioned?<span class="x" onmousemove="('comment',' Though all agree that he is exempt from his liabilities if the owner is in his service. ');"><sup>26</sup></span> Hence [it must be said,] the Tanna states [only] what