Chapter 9, Mishnah 2, continues to deal with monetary laws, focusing on the rights and obligations between a landowner and the one who works the land. The first ten mishnayos in the chapter all open with a single phrase: "Hamekabel sadeh mechavero" - a person who receives a field from his fellow to work it. This refers to a relationship where the farmer might function, depending on the context, as a fixed-produce tenant, a cash renter, or a sharecropper. From the context, we must understand which of these the Mishnah is discussing.
Our Mishnah relates to all these methods equally: there is no practical difference whether the farmer is a sharecropper, a fixed-produce tenant, or a cash renter. The case before us is that he received a field which had a special advantage that made it particularly desirable to him, and this advantage no longer exists. The question is whether he is allowed to deduct from the rental fee he pays, arguing that he paid above market price specifically because of that advantage, and now it is gone.
The Special Advantage in the Field:
"Beis hashelachin" - an irrigated field, which cannot survive on rainwater alone. In this field, there is a convenient water source: a spring flowing within it or a small stream running through it, so the worker does not need to travel far to bring water. This convenience makes it an excellent field worth keeping.
"Sedeh beis ha'ilan" - a grain field with a tree growing in it, such as a carob or fig tree. This is a tremendous advantage, as the fruit comes on its own every year.
Because of this advantage, the farmer agreed to certain conditions regarding the fixed-produce rent or the sharecropping percentages, and his claim is that he added to the price because that advantage appealed to him.
What is the law when "yavesh hamaayan" - the water source in the field dries up, or "niktzatz ha'ilan" - the tree is cut down or stops producing, and that beloved advantage no longer exists?
The Mishnah states: "Eino menakeh lo min chakuro" - he may not deduct from his tenancy fee. The example specified here is a fixed-produce tenant, referring to the set payment he makes, but the same law applies if the cash renter wants to reduce his monetary payment or if the sharecropper wants to reduce his percentage of the profits. Either way, he is not permitted to reduce the payment, since a deal is a deal.
When does this apply?
All this is assuming it was not explicitly stated that this rental depends on and is based upon that special advantage. However, if he explicitly made this a condition - for instance, the sharecropper said: "I want to rent this plot because it is an irrigated field and has a spring," or: "I want to rent and work this field because it has an excellent tree" - the law is different. Similarly, even though the Mishnah does not state this explicitly, the same law applies when the owner was the one who said: "I have an excellent field for you, it has a water source, it has a tree."
In such a case, when the spring dries up or the tree is cut down, "menakeh lo min chakuro" - he may deduct from his tenancy fee. The tenant can say: "We agreed on this high tenancy fee because of that special advantage, and it was clear that this was the deal." Now that there is no more water, irrigation is more difficult, or that there is no more fruit, and the place is less fit for working - the tenancy fee must be adjusted accordingly. This adjustment will, of course, be determined by what the Beis Din decides is fair and customary.
In summary: In this mishnah we learned that one who receives a field from his fellow, and it has a special advantage like a spring or a tree, and that advantage is lost - he does not deduct from the tenancy fee, since the agreement remains in place. However, if it was explicitly stipulated that the rental was made for the sake of that advantage, whether the receiver made the condition or the owner proposed it - he deducts from his tenancy fee, based on the assessment of the Beis Din.