"The Messenger of Allah forbade selling gold for gold, silver for silver, dates for dates, wheat for wheat, barley for barley"- one of them said: "salt for salt," but the other did not say it-"unless it was equal amount for equal amount, like for like." One of them said: "Whoever gives more or takes more has engaged in Riba," but he other one did not say it. "And he commanded us to sell gold for silver and silver for gold, and wheat for barley and barley for wheat, hand to hand, however we wanted."
The Prohibition of Riba in Exchange Transactions
This hadith from Sunan an-Nasa'i 4561 establishes the foundational Islamic rulings regarding riba al-fadl (the riba of excess) in specific commodities known as "ribawi items." The Messenger of Allah ﷺ prohibited the exchange of these six commodities with each other unless certain conditions are met.
The Six Ribawi Commodities
The hadith mentions gold, silver, dates, wheat, barley, and salt as the commodities subject to these special rules. Scholars have categorized these into two types: monetary commodities (gold and silver) and food commodities (the remaining four).
The difference in narration regarding salt demonstrates that while the exact number of commodities may vary in different narrations, the principle applies to items serving as currency or staple foods.
Conditions for Permissible Exchange
When exchanging the same type of commodity (gold for gold, wheat for wheat), three conditions must be met: 1) The exchange must be equal in quantity, 2) It must be of the same type, and 3) The exchange must be hand-to-hand (simultaneous).
The warning "whoever gives more or takes more has engaged in Riba" emphasizes the gravity of violating these conditions, as even a small excess constitutes usury.
Permissible Cross-Category Exchange
The Prophet ﷺ permitted exchanging different categories of commodities (gold for silver, wheat for barley) with flexibility in quantities, provided the exchange is hand-to-hand. This allows for legitimate trade while preventing usury.
The wisdom behind this distinction is that when exchanging different commodities, the natural difference in value justifies difference in quantity, whereas identical commodities should only differ in quantity if there's a delay in payment - which is another form of riba.
Scholarly Application
Classical scholars extended these rules to modern currencies, considering paper money as falling under the category of silver. The principles ensure fairness in transactions and prevent exploitation through subtle forms of usury that may appear in everyday exchanges.
This ruling from The Book of Financial Transactions in Sunan an-Nasa'i protects the economic system from injustice and maintains the purity of commercial transactions in accordance with divine guidance.