"Whenever you pay me such-and-such, you are free." If he pays him that amount, he should become free. If it is said: "If the term and the compensation are changed, it is as if they have rescinded the first kitaba contract and created a second one." We say: No rescission has occurred between them; rather, they intended to change the compensation and the term in a manner that is not valid, so the change is void, and the contract remains as it was. It is also possible that this is valid, as in the first issue. According to this, if they agree upon that, then one of them retracts, he has the right to do so. The same applies in the first issue; if he says: "I will hasten the kitaba payment for you, and you will waive such-and-such amount from it for me," and he says: "Yes," and then one of them retracts before the actual payment, he has the right to do so, because of what we mentioned regarding the fact that the deferred debt is not delayed beyond its term nor is it brought forward; rather, he has the right to pay it before its due date, and the creditor has the right to refuse to accept it at its due date, and that is up to his choice. Thus, if he promises it and then retracts before the act, he has the right to do so.

Section: If the mukatab makes a settlement with his master regarding what is in his liability with something of a different genus, such as if he makes a settlement with him regarding money with wheat or barley, it is permissible, except that it is not permissible to make a settlement with him for something deferred, because it would be a sale of debt for debt. If he makes a settlement with him regarding dirhams for dinars, or regarding wheat for barley, it is not permissible to separate before the taking of possession, because this is in reality a sale, so it is a condition that possession be taken at the session. The Qadi said: It is possible that this settlement is not valid at all, because this is a debt whose condition is deferment, so settlement for it with something else is not permissible, and because it is an unstable debt, it is like the debt of a salam contract. Ibn Abi Musa said: Usury does not operate between the mukatab and his master. According to his opinion, settlement is permissible however it may be, just as it is permissible between the absolute slave and his master. The preferred view is what we have mentioned, and the kitaba debt is distinct from the salam debt; since it differs from other debts for the reasons we have mentioned in this issue, its distinction from the salam debt is even greater. And Allah knows best.