Riba

Riba (Arabic: ربا ,الربا، الربٰوة, ribā or al-ribā, IPA: [ˈrɪbæː]) is an Arabic word used in Islamic law and roughly translated as "usury": unjust, exploitative gains made in trade or business. Riba is mentioned and condemned in several different verses in the Qur'an (3:130, 4:161, 30:39, and most commonly 2:275-2:280). It is also mentioned in many hadith (reports of the life of Muhammad).

While Muslims agree that riba is prohibited, not all agree on what precisely it is. It is often used to refer to interest charged on loans, and the widespread belief among Muslims that all loan or bank interest is riba forms the basis of the $2 trillion Islamic banking industry. However, not all Islamic scholars have equated riba with all forms of interest, nor do they agree whether riba is a major sin or simply discouraged (makruh), or whether it is in violation of Sharia law to be punished by humans rather than by Allah.

The primary form of riba is the interest or other increase on a loan of cash, known as riba an-nasiya. Most Islamic jurists acknowledge another type of riba, the simultaneous exchange of unequal quantities or qualities of some commodity, known riba al-fadl.