We have seen that someone who finds a lost object is obligated to announce his find in an attempt to locate the owner. Furthermore we have learned that the finder must care for the object so that it will be returned in good condition. Can the finder demand to be paid for his services?
The Mishna (30b) rules that the finder cannot ask that he be repaid lost wages for the amount of time that he spend dealing with the lost object, although he can expect to be paid for his time as a po’el – a simple worker. Another option suggested in the Mishna is for him to approach the local Jewish court and arrange to be paid his lost wages in exchange for dealing with the lost item. If there is no local beit din, the Mishna rules that he need not lose his wages, and his own work will take priority over the mitzva of returning the lost object.
In our Gemara, Abaye explains that the payment the finder will receive if he does not make a special arrangement through the beit din is ke-po’el batel shel otah melekha de-batel minah – “like a laborer who has lost out on the work that he missed.” There are a number of opinions offered in explanation of this line.
According to Rashi, it is the amount that a person is willing to accept less than his usual wage were he to be offered an easier, but lower-paying job. It is this lower amount that the person to whom the object is returned must pay.
Several of the rishonim (e.g. Rabbeinu Hananel, the Ri”f, the Ra’avad and others) suggest that when a craftsman has no work, he may be willing to accept less than his usual wage to do work. It is that lower wage that must be paid.