To what extent is it valid that some Companions prohibited ribā al-nasīʾah (usury of delay) while permitting ribā al-faḍl (usury of surplus), and how do banks make a profit if they are prohibited from lending without interest?

Usury (riba) is of two types: Riba an-Nasi'ah (usury of delay) and Riba al-Fadl (usury of surplus). Riba an-Nasi'ah is forbidden by the Qur’an, the Sunnah (definition), and scholarly consensus, while Riba al-Fadl is forbidden by numerous authentic texts. Islamic law has clarified permissible alternatives for banks to generate profit, such as Mudarabah (definition) (profit-sharing) and Murabahah (definition) (cost-plus sale), while emphasizing that lending is a contract of donation and assistance, not intended for profit.