[278]O you who have believed, fear Allah and give up what remains [due to you] of interest, if you should be believers.
[279]And if you do not, then be informed of a war [against you] from Allah and His Messenger. But if you repent, you may have your principal - [thus] you do no wrong, nor are you wronged. - Quran Al-Baqarah(The Cow) 2:278-279 (islam)
O you who have believed, do not consume usury, doubled and multiplied, but fear Allah that you may be successful. - Quran Ali 'Imran(The Family of Imran) 3:130 (islam)
Chapter: Avoiding Consuming The Orphan's Property
It was narrated from Abu Hurairah that the Messenger of Allah said:
"Avoid the seven sins that doom one to Hell." It was said: "O Messenger of Allah, what are they?" He said: "Associating others with Allah (Shirk), magic, killing a soul whom Allah has forbidden killing, except in cases dictated by Islamic law, consuming Riba, consuming the property of orphans, fleeing on the day of the march (to battlefield), and slandering chaste women who never even think of anything touching their chastity and are good believers." - Hadith An Nasai 3671 (islam)