Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

If any one borrowed an animal of his neighbour (to use it for some kind of work), and it got injured and died, he was to make compensation to the owner, unless the latter were present at the time; but not if he were. "For either he would see that it could not have been averted by any human care; or if it could, seeing that he, the owner himself, was present, and did not avert it, it would only be right that he should suffer the consequence of his own neglect to afford assistance" (Calovius). The words which follow, וגו שׂכיר אם, cannot have any other meaning than this, "if it was hired, it has come upon his hire," i.e., he has to bear the injury or loss for the money which he got for letting out the animal. The suggestion which Knobel makes with a "perhaps," that שׂכיר refers to a hired labourer, to whom the word is applied in other places, and that the meaning is this, "if it is a labourer for hire, he goes into his hire, - i.e., if the hirer is a daily labourer who has nothing with which to make compensation, he is to enter into the service of the person who let him the animal, for a sufficiently long time to make up for the loss," - is not only opposed to the grammar (the perfect בּא for which יבא should be used), but is also at variance with the context, "not make it good."