This essay presents a comprehensive exploration of the prohibition of Riba, situating it within the broader framework of Islamic legal and economic philosophy. It begins by outlining the dual dimensions of Shariah—its tarbawī role in moral and spiritual refinement, and its tanẓīmī function in regulating societal structures. Within this framework, the prohibition of Riba emerges as one of the most intricate and debated rulings, with classical scholars themselves admitting to the obscurity of its rationale. The essay then clarifies this by delving into the legal architecture underpinning Islamic commercial law, particularly the bifurcation between goods (ʿurūḍ) and money (thaman), and how each is treated differently under transactional regulations.
The discussion advances by defining Riba in its two primary forms—Riba al-Nasīʾah and Riba al-Faḍl—and by establishing its textual and jurisprudential basis in both the Qur’an and Sunnah. It then examines the types of assets to which the prohibition applies, the legal causes (ʿilal) that trigger its enforcement, and why certain count-based items are excluded. A key contribution of the essay is its detailed analysis of how Shariah deliberately discards quality differences in Ribawi items to block avenues for unjustified enrichment. It further presents the legal and economic wisdoms behind conditions like immediacy (taqābuḍ) and equivalence (tasāwī), highlighting how these prevent the monetisation of time and synthetic wealth creation. The latter sections explore modern fiat currencies, affirming their inclusion within the ambit of Riba rules, and culminate in a broader articulation of Islamic economic philosophy—one rooted in real productivity, equitable risk-sharing, and moral integrity, in stark contrast to the exploitative dynamics of Riba-based systems.