What is the ruling on usury (riba) in Islam?

Usury (riba) is forbidden by the Qur'an, the Sunnah, and scholarly consensus (ijma'). Many verses in the Qur'an attest to this, including: "O you who have believed, fear Allah and give up what remains [due to you] of riba, if you should be believers. And if you do not, then be informed of a war [against you] from Allah and His Messenger." (Qur'an 2:278-279). Prophetic narrations (Ahadith) also warn against it, such as his (peace be upon him) saying: "Avoid the seven destructive sins… [one of them is] consuming riba." And his saying: "Allah has cursed the one who consumes riba, the one who pays it, the one who writes it down, and the two who witness it," and he said: "They are all equal (in sin)." Consensus has been reached on the prohibition of riba, and whoever denies its prohibition has disbelieved.