Those who eat Ribaa (usury) will not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaitan (Satan) leading him to insanity. That is because they say: “Trading is only like Ribaa (usury),” whereas Allaah has permitted trading and forbidden Ribaa (usury). So whosoever receives an admonition from his Lord and stops eating Ribaa (usury) shall not be punished for the past; his case is for Allaah (to judge); but whoever returns [to Ribaa (usury)], such are the dwellers of the Fire – they will abide therein.

(Al-Baqarah 2:275)