According to the universal consensus of classical Islamic scholarship, Riba (الربا) is the Quranic term for any unjust, exploitative surplus or increase in loans and specific trade exchanges, often translated as usury or interest. The Quran, in verses such as 2:275, makes an explicit and absolute distinction: "Allah has permitted trade (al-Bay') and has forbidden Riba." Tafsir by classical authorities like Ibn Kathir and Al-Qurtubi explains that this prohibition is rooted in divine wisdom to prevent economic exploitation, social inequality, and the erosion of compassion. While trade involves risk-sharing and value creation, Riba guarantees a return for the lender from the borrower's need, regardless of the outcome, creating a system that benefits the wealthy at the expense of the vulnerable. The prohibition covers two main forms: Riba an-Nasi'ah (interest on debt) and Riba al-Fadl (unequal exchange of like commodities). The severe Quranic warnings, including a declaration of "war from Allah and His Messenger" (2:279), underscore its gravity, positioning the avoidance of Riba as a cornerstone of Islamic economic ethics and a fundamental act of faith.