The Book of Financial Transactions - Sunan an-Nasa'i 4558

"The Messenger of Allah said: '(Exchanging) gold for silver is Riba unless it is done on the spot. (Exchanging) dates for dates is Riba unless it is done on the spot. (Exchanging) wheat for wheat is Riba unless it is done on the spot. (Exchanging) barley is Riba unless it is done on the spot."'

Scholarly Commentary

This hadith establishes the fundamental prohibition of Riba al-Fadl (excess interest) in spot exchanges of certain commodities. The Prophet ﷺ specifically identified six commodities that fall under this ruling: gold, silver, dates, wheat, barley, and salt (mentioned in other narrations).

The condition "on the spot" (hand to hand) means both parties must take immediate possession during the transaction session without delay. If there is any deferment in delivery from either side, it becomes prohibited Riba.

The wisdom behind this prohibition lies in preventing exploitation through unequal exchanges of the same commodity type, which was a common form of usury in pre-Islamic times. Scholars have derived from this that when exchanging identical commodities from the same category, the exchange must be equal in measure and immediate in delivery.

Legal Classifications

The six commodities mentioned are classified into two monetary categories (gold and silver) and four food categories (dates, wheat, barley, salt). Modern scholars extend these categories to include contemporary currencies and staple foods.

When exchanging within the same category (gold for gold, wheat for wheat), the quantities must be equal and exchange must be immediate. When exchanging across categories (gold for wheat), the exchange rate may differ but delivery must still be immediate.

Contemporary Application

This ruling applies directly to modern currency exchanges - exchanging different currencies must be done spot rather than forward contracts with deferred delivery. Similarly, trading identical commodities on spot markets must involve immediate transfer of ownership.

The principle derived safeguards economic transactions from uncertainty (gharar) and exploitation, ensuring fairness in bilateral exchanges of monetary and consumable commodities.