He mentioned charity, trade, and usury. The injustice and wrongful consumption of wealth involved in usury are more evident than in gambling, for the usurer takes a guaranteed surplus from someone in need. Allah therefore punished him with the opposite of what he intended, saying:

“Allah destroys usury and gives increase to charity.”

The gambler, by contrast, may win and thereby wrong another person; the victim may be rich or poor. Wronging someone poor and needy is more serious than wronging someone rich. Injustice in which the powerful party is certain to be the wrongdoer is more serious than injustice in which the wrongdoer is not determined beforehand. For a wealthy, powerful person to wrong someone weak and helpless is more reprehensible than two wealthy, powerful people wronging one another when it is not known which will be the wrongdoer.

Thus, usury involves greater financial injustice than wagering. Nevertheless, its prohibition came later, and it was the last thing Allah Most High prohibited in the Quran. If gambling involved nothing more than wagering, it would have been less serious than usury, whose prohibition came later.

The Lawgiver has permitted certain forms of contractual uncertainty to meet a need. For example, He permitted stipulating that the fruit of date palms be included with the trees after pollination, as something subsidiary to them. He also permitted sales in bulk without exact measurement, and other such transactions. As for usury, none of it was permitted. Rather, He allowed quantities to be assessed by estimation instead of measurement by volume when needed, just as He allowed dry ablution out of need when water is unavailable. Estimation determines a quantity on the basis of probable judgment, whereas measurement by volume determines it with certainty. Resorting to probable judgment instead of certainty is permissible when needed.

It thus becomes clear that usury is more serious than wagering that involves nothing beyond the wrongful consumption of wealth. Gambling, however, is pursued for play and competition, and a person is forbidden to engage in it because it corrupts his mind as well as his wealth, including by turning him away from the remembrance of Allah and from prayer.

Both intoxicants and gambling engender enmity and hatred and divert people from the remembrance of Allah and from prayer to a greater extent than usury and other invalid transactions.