As for usury, its prohibition in the Quran is even more emphatic. Thus Allah Most High says:

“O you who believe, fear Allah and relinquish whatever remains of usury, if you are truly believers. If you do not, then be informed of war from Allah and His Messenger.” [al-Baqara: 278–279] [al-Baqara: 278, 279]

The Prophet (peace and blessings be upon him) counted it among the major sins, as al-Bukhārī and Muslim narrated in their two Sahih collections from Abū Hurayra (may Allah be pleased with him). Allah also mentioned that He forbade the Jews wholesome things that had been lawful to them because of their wrongdoing, their hindering others from the path of Allah, their taking usury, and their wrongful consumption of people’s wealth. He, Glorified is He, further stated that He destroys usury just as He makes charitable gifts grow; both facts have been confirmed by people’s experience.

This is because usury, by its very nature, is resorted to only by someone in need. A person of means would not take one thousand now in exchange for twelve hundred later if he had no need for that thousand. Only someone in need takes money in exchange for repaying its equivalent plus an increment at a later date. That increment therefore wrongs the person in need. This is unlike gambling, in which the wronged party is not [in need], nor does he need to enter into the transaction. Some of its forms may even be free of injustice if the item sold is later found to have the qualities that both parties expected. Usury, however, necessarily entails injustice toward the person in need, and for this reason it is the opposite of charity. Allah did not leave the wealthy without obligation; rather, He required them to give to the poor, for the welfare of rich and poor alike, in both religion and worldly life, cannot be complete without this. If usury is instead exacted from the poor person, he is like someone to whom another man owes a debt but who is denied what is due to him and then subjected to an additional injustice, even though the creditor needs what he is owed. This is among the gravest forms of injustice. Because of its gravity, the Prophet (peace and blessings be upon him) cursed the one who consumes usury—meaning its recipient—the one who pays it—meaning the needy person who pays the increment—its two witnesses, and its scribe, because they assist in it.