The First Topic: Definition of Selling a Debt for a Debt
· Linguistic Definition: "Kala" (to delay) comes from the phrase "Kalaa’ahu Allah yakla’uhu" - which means, "Allah protected him" – derived from the verb “kala,” which means protection. It can also mean to delay, as in "the debt was delayed. [341] - See: "Al-Miṣbāḥ al-Munīr" by al-Fayyūmī (2/540). "
· Islamic (Shari'a) Definition: It is the sale of a debt for a debt [342] - For example, the price may be deferred, and the commodity may also be deferred; thus, the delivery and receipt of the price and the commodity do not occur. It has several forms, one of which is that a man may lend another man one hundred ṣāʿ of wheat for a month, for example, with the price being deferred. ((Al-Insāf)) by al-Mardāwī (5/37), and see: "Al-Awsat" by Ibn    al-Mundhir (10/118- 119); "Muṣannaf ʿAbd al-Razzāq" (8/90). .
The Second Topic: The Ruling on Selling a Debt for a Debt.
Selling a debt for a debt is prohibited.
The Evidences:
Firstly: From the Sunnah:
On the authority of Ibn 'Abbas (رضي الله عنهما ), he said: “The Prophet صلى الله عليه وسلم arrived in Madinah, and the people used to pay in advance for the fruits of a year or two years. He said: ‘Whoever pays in advance for dates, let him do so for a known measure, a known weight, and for a known time. [343] -It was narrated by al-Bukhārī (2240) and Muslim (1604), and the wording is from him. ’”
Reasoning:
The Prophet’s (صلى الله عليه وسلم) saying: "Whoever pays in advance" implies that the payment must be given because the transaction cannot be considered valid unless the payment is handed over before parting [344] - See: "Al-Um" by Al-Shafiʿi (3/95), "Sharh Al-Zarkashi on Mukhtasar Al-Khiraqi" (4/14) . Since the Prophet (صلى الله عليه وسلم) stipulated that the price must be fully received, this indicates the prohibition of selling a debt for a deb.
Secondly: From Ijma' (Consensus):
Ahmad ibn Hanbal [345] - Ibn Taymiyyah said: "Ahmad said: There is no authentic Hadith regarding it, but it is consensus." "Nazariyyat Al-‘Aqd" (p. 235). Al-Shawkani reported this and said: "It is consensus, as Ahmad stated." "Nail Al-Awtar" (5/186). , Ibn al-Munthir [346]- Ibn Al-Mundhir said: "The mention of the prohibition of a loan with another loan. The scholars have unanimously agreed that selling a debt for a debt is not permissible. For example, if a man gives another man dinars in exchange for ten measures of wheat to be delivered at a specified time, and the time comes and the one who owes the food does not bring it, he may buy the measures from the lender, who is due payment, for fifteen dinars at a second specified time. This is a debt that has transformed into a similar debt. Another example is if a man lends another man ten measures of wheat to be delivered at a specified time, without receiving the price, this would also be a debt for a debt." "Al-Awsat" (10/119). , Ibn Qudamah [347] - Ibn Qudamah said: "If a man owes another man gold, and the latter owes him silver, and they exchange what is in their debts, this transaction is not valid. Al-Layth and Al-Shafi'i held this view, while Ibn Abdul Barr narrated from Malik and Abu Hanifah that it is permissible because a present debt is like present property; therefore, it is allowed to purchase silver with gold without specifying a particular amount. Our position is that this is a sale of a debt for a debt, which is not permissible according to consensus." "Al-Mughni" (4/37). , and Imam al-Nawawi [348] - Al-Nawawi said: "It is not permissible to sell a deferred payment for another deferred payment; for example, if one says: 'Sell me a garment on credit, to be paid in a month, for a deferred dinar due at that time,' and the other replies: 'I accept,' this transaction is invalid without any disagreement." "Al-Majmu'" (9/400). reported this consensus.