it was stipulated in the sales contract. The buyer is compelled to do so, and if the judge finds it, he shall hand it over to the seller, because the sales contract was concluded upon it, thus it resembles the option (khiyar). The judge (al-Qadi) said: Regarding what is other than weighed or measured goods, the pledge becomes binding upon the mere conclusion of the contract. The discussion with them regarding this has already passed at the beginning of the chapter. Furthermore, it is a pledge, so it does not become binding before possession (qabd), just as if it were not stipulated in the sale, or like items other than weighed or measured goods. The option and the deferment (ajal) become binding by condition because they are among the appendages of the sale and do not stand alone, whereas a pledge is a contract that stands alone by itself and is not an appendage. Moreover, the option and deferment are established by word and do not require delivery; thus, mere word sufficed for their establishment, unlike the pledge. As for the guarantor, there is no disagreement that the guarantee is not binding upon him, since the occupation of his liability and the performance of another person's debt are not binding upon him through the stipulation of another. If he promised him that he would guarantee, and then did not do so, it is not binding by legal judgment, just as if he promised him that he would sell to him, and then refused. Whenever the buyer does not fulfill his condition for the seller, he (the seller) has the right to annul, just as if he stipulated for him a quality in the price and he did not fulfill it. This is because he is one of the contracting parties, and when he does not fulfill what he stipulated in the contract, the option is established for the other party, like the seller if he stipulated the sold object to be of a certain quality and it turns out to be otherwise.

Section: If he stipulates a pledge or a specific guarantor, and he brings someone other than them, it is not binding upon the seller to accept it, even if what he brought is better than what was stipulated, such as bringing something of greater value than what was stipulated, or a guarantor more reliable than the specified one. This is because he contracted upon a specific [person or thing], and he is not obligated to accept anything else, just as in a sale. Furthermore, the purpose varies according to the distinct entities; some are easy to sell and to satisfy [the debt] from their price, others involve less expense and are easier to preserve, and some liabilities are more solvent than others and easier to fulfill. Thus, he is not obligated to accept other than what he specified, like all other contracts.