(Mishnah): One who borrowed a cow and 'borrowed' its owner (to work) with it; or he borrowed a cow and hired the owner with it; or he first hired the owner and then borrowed the cow, and it died, he is exempt, as the pasuk states (Shemos 22, 14), "...if its owner is with it, he shall not pay''.

But if he first borrowed the cow and then borrowed or hired its owner and it died, he is liable, as the pasuk states (ibid, 13), "...if its owner is not with it, he shall surely pay''.

(Gemara) - R. Ila: From the words "if its owner is not with it, he shall surely pay'', do we not understand that "if its owner is with it, he shall not pay''? Rather, this teaches that if he borrowed the cow and hired the owner with it, even if the owner is ploughing elsewhere and it died, he is exempt.

The Mishnah taught: But if he borrowed the cow and then borrowed or hired its owner and it died, he is liable.

R. Ila: From the words "if its owner is with it, he shall not pay'', do we not understand that "if its owner is not with it, he shall surely pay''? Rather, this teaches that if he borrowed the cow and did not hire the owner with it, even if the owner is ploughing with it and it died, he is liable.