unless there is no currency in the town of ten to a dinar except for one type, in which case that description points to it. The same rule applies to sale.

Section: If a man has gold in the liability (dhimmah) of another man, and the other has silver coins (dirhams) in his liability, and they exchange them based on what is in their liabilities, it is not valid. This was the view of al-Layth and al-Shafi'i. Ibn 'Abd al-Barr narrated from Malik and Abu Hanifah that it is permissible, because the present liability is like a present tangible object (ayn); and for this reason, it is permissible to purchase dirhams with dinars without specification. Our evidence is that it is the sale of a debt for a debt, and that is not permissible by consensus. Ibn al-Mundhir said: The scholars have reached consensus that the sale of a debt for a debt is not permissible. Ahmad said: It is indeed a consensus. Abu 'Ubayd narrated in "al-Gharib" that the Prophet (peace be upon him) prohibited the sale of the delayed for the delayed (al-kali' bi-al-kali'), interpreting it as debt for debt. However, al-Athram narrated from Ahmad that he was asked: "Is there a valid hadith regarding this?" He said: "No." The Sarf (currency exchange) is only valid without specification on the condition that they take possession in the session; thus, taking possession and specification in the session serves the same purpose as their presence at the time of the contract. If a man has dinars owed by a man, and he pays him in dirhams bit by bit, you must examine: if he gives him each dirham according to its calculated rate from the dinar, it is valid. Ahmad stated this clearly. If he does not do that, and they calculate the account later, and he exchanges them at the time of the settlement, it is not permissible. He also stated this clearly, because the dinars are a debt and the dirhams have become a debt, so it becomes the sale of a debt for a debt. If one of them takes possession of what is owed to him by the other, then exchanges it for a tangible object and a liability, it is valid. When he gives him the dirhams bit by bit, and he did not pay him that at the time he handed them over, but then he brought them and they appraised them, then he calculates them according to their value on the day of payment, not the day he handed them over, because before