dates for dates, and salt for salt—equal for equal, like for like, hand to hand. If these kinds differ, then sell as you wish, provided the exchange is hand to hand.

Most of the riba people fall into today concerns the first two kinds: gold and silver, for foodstuffs are seldom bartered and riba in them is likewise rare. The great majority of violations therefore occur in money. When paper currency—issued as a substitute for gold and silver—first appeared, the scholars, may Allah have mercy on them, disagreed sharply about its ruling, to the point that more than six opinions were recorded. Each scholar advanced his own reasoning.

The view that is closest to the truth is that paper money is subject to riba al-faḍl (surplus riba) but not to riba al-nasīʾa (deferred riba); that is, only surplus riba applies to it, not deferred riba, when the species involved differ. Accordingly, it is permissible for me to give you 10 riyals in paper notes and take from you 9 riyals in metal coins, or the like, because the qualities of the two are different. The hadith says, “When these kinds differ, then sell as you wish.”

True, the nominal value of the two forms of money is the same by force of law and government decree, but if we look at their intrinsic reality we find that iron is not the same as paper; even their inherent value differs. Imagine taking a lump of iron and a scrap of paper from the street and trying to treat them as equal—you would immediately see the disparity. The genus is different and the value is different. Were it not for the government’s decision to deem the one equal to the other in purchasing power, they would never be equal in value. On that basis, they fall under the Prophet’s statement