Riba (usury) is one of the types of exploitation in transactions. It entails great harm and involves unlawful earnings and taking extra money wrongfully. Therefore, it has been prohibited in all the laws that have been revealed. Riba has various types, all of which are prohibited. Riba al-Fadl (usury of surplus) is one type and it means selling an item that is subject to Riba rulings for another of the same type with excess in one of the two, like selling a gold dinar for two dinars and a silver dirham for two dirhams, which have been prohibited by the Prophet (may Allah's peace and blessings be upon him) in this Hadīth. An example of this is selling new gold or silver coins for those that weigh more, thus, taking in return for every one coin two old gold or silver coins. The Shariah states that such a sale is not to be concluded unless they are both alike and equal in weight, regardless of the quality or the inferiority, and on condition that the two currencies are present during the sale transaction and are exchanged hand to hand. So, equality and exchange during the contract session are conditions when selling an item for another item of the same type. However, if the type varies and the cause remains - like selling gold for silver - equality is no longer required, but exchange during the contract session is still a condition, as the Prophet (may Allah's peace and blessings be upon him) said in Sahīh Muslim Collection: "If these classes differ, sell as you wish as long as payment is made hand to hand." The Hadīth indicates the prohibition of Riba al-Fadl (usury of surplus)..