that Malik bin Aus said, "I was in need of change for one-hundred Dinars. Talha bin 'Ubaidullah called me and we discussed the matter, and he agreed to change (my Dinars). He took the gold pieces in his hands and fidgeted with them, and then said, "Wait till my storekeeper comes from the forest." `Umar was listening to that and said, "By Allah! You should not separate from Talha till you get the money from him, for Allah's Messenger (ﷺ) said, 'The selling of gold for gold is Riba (usury) except if the exchange is from hand to hand and equal in amount, and similarly, the selling of wheat for wheat is Riba (usury) unless it is from hand to hand and equal in amount, and the selling of barley for barley is usury unless it is from hand to hand and equal in amount, and dates for dates, is usury unless it is from hand to hand and equal in amount"
Hadith Commentary: The Prohibition of Riba in Sales
This narration from Sahih al-Bukhari 2174 in the Book of Sales and Trade demonstrates the strict prohibition of Riba (usury/interest) in Islamic commercial transactions, particularly regarding the exchange of similar commodities.
The Incident and Its Context
Malik bin Aus needed to exchange one hundred gold dinars, and Talha bin 'Ubaidullah agreed to facilitate this transaction. However, when Talha took the gold coins and began handling them while asking Malik to wait for his storekeeper, this created a situation where the exchange was not immediate.
'Umar ibn al-Khattab, recognizing the potential violation of Islamic commercial principles, immediately intervened to prevent what could have become a prohibited transaction.
The Prophetic Prohibition
The Messenger of Allah (ﷺ) clearly prohibited the exchange of gold for gold, wheat for wheat, barley for barley, and dates for dates unless two conditions are met: the exchange must be equal in quantity and must occur hand-to-hand (meaning immediately, without delay).
This ruling falls under the category of "Riba al-Fadl" (the riba of excess), where exchanging the same type of commodity with inequality or delay constitutes usury.
Scholarly Analysis of the Conditions
The requirement of "hand-to-hand" (yadan bi yadin) means the exchange must be completed in the same session without postponement of either delivery. Any delay in receiving one of the countervalues renders the transaction invalid.
The condition of equal measure applies specifically to commodities used as currency (gold, silver) or staple foods measured by weight or volume. The wisdom behind this is to prevent exploitation and ensure fairness in basic necessities.
Practical Implications
This hadith establishes that in currency exchange (gold for gold, or silver for silver), the amounts must be exactly equal and the exchange must be immediate. There can be no deferment of payment or receipt.
For modern applications, this principle extends to paper currency exchanges of the same type, requiring immediate and equal exchange to avoid any element of riba.
The Wisdom Behind the Prohibition
This ruling protects society from economic exploitation and ensures justice in commercial transactions. It prevents the accumulation of wealth without genuine effort and maintains the stability of the monetary system.
The immediate exchange requirement eliminates uncertainty (gharar) and prevents disputes that may arise from deferred transactions.