משנה אויף שמות 22:14

All craftsmen are accounted paid guardians. But all that have said, “Take what is yours and give me the money”, are accounted unpaid guardians. If one man said to another, “Guard that for me and I will guard this for you”, he is accounted a paid guardian. If one said, “Guard this for me”, and the other said “Put it down in front of me”, he is accounted an unpaid guardian.

If one borrowed a cow together with the service of its owner, or hired its owner together with the cow, or if he borrowed the service of the owner or hired him, and afterward borrowed the cow, and the cow died he is not liable, for it is written, “If its owner was with it no restitution need be made” (Exodus 22:14). But if he first borrowed the cow and afterward borrowed or hired the service of its owner, and the cow died, he is liable, for it is written, “Its owner not being with it, he must make restitution” (Exodus 22:13).