שמות כב ,ו: כֶּסֶּף אוֹ־כֵלִים
There are four categories of שומרים (watch people): 1) One who does so without compensation (as a favor); 2) one who is paid; 3) one who leases; and 4) a borrower. Verses 6 thru 13 discuss the various laws to these watch people. The Torah does not specify which verses would apply to category 1 & 2. Chaza”l teach us that verses 6-8 apply to one who watches as a favor; whereas verses 9-12 refer to one who receives compensation.
The Sforno explains logically how Chaza”l reached their opinion. The former verses deal with inanimate objects which are easily guarded hence it refers to one who watches without compensation. The Sforno adds that the Torah is speaking about a well-to-do person who must guard in own possessions and it is no great bother to watch another’s as well. Verse 9, however, speaks of livestock which demands time and attention and thus effort. Therefore, it is logically that in that circumstance, a watch person would be paid to perform this service.
