compensation. If it occurs in a manner where the inability to provide the compensation is realized, it is not valid, just as if one were to enter into a salam contract for something that will not be found at its maturity. It differs from a sale because in a sale, the inability to provide the compensation is not realized, for the buyer owns the sold item, whereas the slave owns nothing, and what is in his hand belongs to his master. In the installment system, there are two points of wisdom: one pertains to the mukatab, which is lightening the burden upon him, because paying in installments is easier, and this is why debts are usually divided into installments for the insolvent to lighten their burden. The second pertains to the master, which is that the period of the kitaba is usually long; if it were for a single installment, his inability would not appear until the end of the period, and if he became unable, he would return to slavery and the master would lose his services during the entire duration of the kitaba without obtaining any benefit. If it is divided into installments, and he fails to pay the first installment, its period is brief, and if he fails to pay what follows, the master has already gained a benefit from what he took of the installments before the failure. When this is established, the minimum is two installments or more. This is the school of al-Shafi'i. It is reported from Ahmad that he said: Some people say: one installment. Others say: two installments. And two installments is more beloved to me. This may mean that I hold the view that it is not permissible except in two installments. It may also mean that two installments are recommended, while one is permissible. Ibn Abi Musa said: This is by way of preference, and if the entire money is placed in a single installment, it is permissible, because it is a contract for which deferment is stipulated, so it is permissible for it to be until a single term, like the muslam fihi. Also, the consideration of deferment is to enable the delivery of the compensation, and this is achieved with a single installment. The argument for the first [position] is what was narrated from Ali, may Allah be pleased with him, that he said: "Kitaba is on two installments, and the 'iita' (giving) is from the second." This necessitates that this is the minimum upon which a kitaba is permissible, for more than two is permissible by consensus. It was narrated from Uthman, may Allah be pleased with him, that he was angry with a slave of his and said: "I shall punish you, and I shall enter into a kitaba with you upon two installments." If less than this were permissible, he would have punished him with it.