سورة Al-Baqarah ( The Cow ) - الآية 275

Those who swallow usury cannot rise up save as he ariseth whom the devil hath prostrated by (his) touch. That is because they say: Trade is just like usury; whereas Allah permitteth trading and forbiddeth usury. He unto whom an admonition from his Lord cometh, and (he) refraineth (in obedience thereto), he shall keep (the profits of) that which is past, and his affair (henceforth) is with Allah. As for him who returneth (to usury) - Such are rightful owners of the Fire. They will abide therein.