What is usury (riba), and what are the verses prohibiting it and its punishment in Islam?

Usury results in the destruction of blessings in this world and severe torment in the Hereafter. Allah Almighty says: (Allah destroys usury and gives increase for charities). And concerning those who do not repent in this world, Allah Almighty says: (And if you do not, then be informed of a war from Allah and His Messenger). It has been narrated in a hadith that the usurer will be tormented by swimming in a sea of blood, and whenever he approaches the edge, a man will throw a stone into his mouth.