Its quality and inferiority must also be specified, because quality and inferiority produce an evident difference in price.

It is not valid to stipulate the very worst or the very best; rather, one should say: good or inferior. If he brings what was stipulated, or something better of the same type—even before its due date—and there is no harm in taking possession of it, the buyer must accept it.

His statement: “It is not valid to stipulate the very worst or the very best,” means that if he says, “of the very best quality,” or “of the very worst quality,” they say that this is invalid.

For example, I enter into a salam contract with you, paying one hundred riyals for one hundred sāʿs of wheat of the very best quality. The author says: This is invalid, because there is no good quality without there being something better than it. What is of the very best quality in one town may be of the very worst quality in another. So what are we to do when he says, “of the very best quality”?! Moreover, even what is of the very best quality in a town may merely be the best available in the market, while people have something better than it in their homes. Thus, stipulating the very best is invalid.

The same applies to stipulating the very worst, for there is no inferior quality without there being something worse than it. The scholars differed concerning this issue, holding three views:

The first view is that of the author: it is not valid to stipulate either the very worst or the very best. (1) The reason is that there is no good quality without something better than it, and likewise there is no inferior quality without something worse than it. Therefore, this description cannot be realized; and since it cannot be realized, it is like something whose attributes cannot be precisely defined, such as jewels and the like.

The second view is that it is valid to stipulate the very worst, but not the very best, if the seller—that is, the party obligated to deliver in the salam contract—stipulates that it is the very worst