He reported God’s Messenger as saying, "Do not sell gold for gold unless it is like for like, and do not make one amount greater than the other; do not sell silver for silver unless it is like for like, and do not make one amount greater than the other; and do not sell for ready money something to be given later*.” A version has, "Do not sell gold for gold or silver for silver unless both are of equal weight.”(Bukhari and Muslim.)* Payment is not to be made till the goods are received.
Commentary on the Prohibition of Riba al-Fadl
This noble hadith from the Book of Business Transactions in Mishkat al-Masabih (Reference: Mishkat al-Masabih 2810) establishes the fundamental prohibition of Riba al-Fadl, which is the excess in exchange of specific commodities. The Messenger of God ﷺ explicitly forbade the exchange of gold for gold or silver for silver unless it is equal in weight and hand-to-hand (simultaneous exchange). This ruling prevents any hidden usury that might occur when these ribawi items are traded with disparity.
The Six Riba Commodities
The scholars of Islam have derived from this and similar ahadith that there are six commodities subject to these rules: gold, silver, wheat, barley, dates, and salt. When exchanging the same kind (gold for gold, etc.), two conditions must be met: 1) exact equality in weight/measure, and 2) immediate, simultaneous exchange (hand-to-hand).
If the commodities are of different kinds but fall under the same category (e.g., gold for silver), then immediate exchange is required, but equality in weight is not; the current market rate applies. This is known as Sarf (currency exchange).
Prohibition of Credit Sales in Specific Exchanges
The final portion of the hadith, "do not sell for ready money something to be given later," prohibits the sale where one item is exchanged immediately but the counter-value is delayed. This delay (nasī'ah) introduces Riba al-Nasi'ah, the usury of delay. The wisdom is to eliminate ambiguity and potential dispute, ensuring transactions are clear, fair, and free from exploitation.
Practical Application & Divine Wisdom
The divine law (Shari'ah) in these commercial rulings seeks to establish justice and remove harm. By mandating equality and immediacy in the exchange of these essential commodities, which often serve as monetary standards or staple foods, Islam closes all doors to injustice and economic exploitation. It fosters a market based on transparency and mutual benefit, protecting the wealth of the community and purifying transactions from any element of doubt or usury.