Somebody rents a field of wheat and agrees to a fixed payment of 10 kor, measurement of wheat, every year. If the field is damaged—for example, if a heavy storm comes and damages the crops, leaving very low-quality crops—the renter can still give the owner 10 kor of wheat from this field. He is not obligated to buy better-quality wheat from the market to pay his rent. It is understood that, if he is able to, he automatically uses the wheat from his field.
The opposite is true as well. If the wheat in the field is super high quality, the renter cannot say to the owner, “You know what? There’s super high-quality wheat from the field I rented. I’m stashing that away and putting it in my storehouse. I’m going to get you your 10 kor of wheat, but I’m going to get lower-quality or regular-quality wheat from the marketplace and give that to you. I want to keep the higher-quality wheat.” He is not allowed to do that. He gives the owner the 10 kor of wheat that grew in his field, even though they agreed on a measurement. They agreed on 10 kor. There is an understanding that, if they are able to, part of this rental agreement is that the wheat from the field will be used as payment.
Of course, there are situations where they cannot use the wheat from the field for whatever reason. Let’s say nothing grew. Then he would still be obligated to give him 10 kor of wheat, but he would have to get it from the marketplace. Here, when the wheat from the field grew, part of the quality of what grew in the field is also part of what the owner is agreeing on with the renter. Therefore, he could give him no matter what the wheat is, good quality or not such good quality. That is what he would hand over to the owner of the field.