Abu Huraira related that the Prophet said: On the night of the Miraj I came upon a group of people whose bellies were like houses. They were full of snakes which could be seen from outside their bellies. I asked Gabriel who they were, and he told me that they were the people who had practiced Riba (Interest). (Ahmad, Ibn Maja)
Abdullah ibn Hanjalah related that the Prophet said: A dirham of Riba (interest) knowingly taken by a man is a sin worse than committing Zina (fornication) 36 times (Ahmad, Daraqutni).
“And they were not commanded except to worship Allah, [being] sincere to Him in religion, inclining to truth, and to establish prayer and to give Zakah. And that is the correct religion.” (Quran 98:5)
Abbas related that a man asked the Prophet, Tell me what should I do to be admitted to Paradise and he (the Prophet) answered: Worship Allah associating nothing with Him, observe Salat, pay Zakah and strengthen the ties of kinship. (Bukhari, Muslim)
