The Prophet Muhammad (Sal-allahu-aleihi-wasallam) cursed the devourer of usury, its payer, its scribe, and its two witnesses. And he said that they are equal (in sins).
Narrated by Jaber (Radi Allah Ta'lah Anhu); Muslim transmitted it. Hadith No.2807 of Mishkat Al-Masabih.
The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Usury has got seventy divisions. The easiest division of them is a man's marrying his mother.
Narrated by Abu Huraira (Radi Allah Ta'lah Anhu); Ibn Majah transmitted it. Hadith No.2826 of Mishkat Al-Masabih.
The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "Though usury increases, its effect indeed turns towards decrease.
Narrated by Ibn Masud (Radi Allah Ta'lah Anhu); Ibn Majah transmitted it. Hadith No.2827 of Mishkat Al-Masabih.
The Messenger of Allah (Sal-allahu-aleihi-wasallam) observed: Avoid the seven noxious things. It was said (by the hearers): What are they, Messenger of Allah? He (the Holy Prophet Sal-allahu-aleihi-wasallam) replied:
Associating anything with Allah,
magic,
killing of one whom God has declared inviolate without a just cause,
consuming the property of an orphan,
and consuming of usury,
turning back when the army advances,
and slandering modest women who are believers, but unwary.
Narrated by Abu Huraira (Radi Allah Ta'lah Anhu); Sahih Muslim transmitted it. Book No. 1 Hadith No.161 of Sahih Muslim.
The Prophet Muhammad (Sal-allahu-aleihi-wasallam) said, "A Dirham of usury a man devours with knowledge is greater than 36 fornications.
Narrated by Abdullah bin Hanjalah (Radi Allah Ta'lah Anhu); Ahmad and Darqutni transmitted it. Hadith No.2825 of Mishkat Al-Masabih.
The Prophet (Sal-allahu-aleihi-wasallam) said, "This night I dreamt that two men came and took me to a Holy land whence we proceeded on till we reached a river of blood, where a man was standing, and on its bank was standing another man with stones in his hands. The man in the middle of the river tried to come out, but the other threw a stone in his mouth and forced him to go back to his original place. So, whenever he tried to come out, the other man would throw a stone in his mouth and force him to go back to his former place. I asked, 'Who is this?' I was told, 'The person in the river was a Riba-eater."
Narrated by Samura bin Jundab (Radi Allah Ta'lah Anhu); Sahih Bukhari transmitted it. Vol 3 Hadith No.298 of Sahih Bukhari.