The former is more analogically sound. If he says, 'I have become surety for so-and-so if I bring him by such-and-such a time, otherwise I am a surety for so-and-so,' or 'a guarantor of the wealth that is upon so-and-so,' it is not valid in either case according to the judge (al-Qadi), because the first is time-bound and the second is suspended upon a condition. Abu al-Khattab said: 'It is valid in both cases.' As for if he says, 'I have become surety for one of these two men,' it is not valid according to all of them, because it is unknown in the present and in the outcome.

Section: If he says, 'I have become surety for the person of so-and-so, on the condition that so-and-so, the surety, be absolved,' or 'on the condition that you absolve me from the suretyship,' it is not valid, because he has stipulated a condition that is not binding to fulfill, so it becomes corrupt (fasid), and the suretyship is corrupted by it. It is possible that the suretyship might be valid, because he stipulated the transfer of the security that is upon the surety to him. Based on this, the suretyship is not binding upon him unless the creditor (al-makful lahu) absolves the first surety, because he only acted as surety with this condition, so his suretyship is not established without his condition. If he says, 'I have become surety to you for this debtor, on the condition that you absolve me from the suretyship for so-and-so,' or 'I have guaranteed this debt for you, on the condition that you absolve me from the guarantee of the other debt,' or 'on the condition that you absolve me from the suretyship for so-and-so,' two positions have been derived regarding this, and the most sound is that it is not valid, because he stipulated the dissolution of a contract within a contract, so it is not valid, like a sale with the condition of dissolving another sale. Likewise, if he stipulated in the suretyship or guarantee that the creditor or the debtor (al-makful bihi) provide another person as surety, or guarantee a debt upon him, or sell him something he specified, or lease him his house, it would not be valid for the reason we have mentioned.

Section: If two people stand surety for one person, it is valid. Whichever of them pays the debt, the other is absolved, as we have mentioned regarding the guarantee. If the person for whom the suretyship was provided (al-makful bihi) presents himself, his two sureties are absolved, because he has performed what was required of the two sureties on his behalf, which is the producing of his person, so their liability is cleared, just as if he had paid the debt. If one of the two sureties produces him, the other is not absolved, because one of the two securities has been dissolved without fulfillment, so the other is not dissolved, just as if he had absolved one of them, or one of the two pledges (rahn) was released without payment of the right.