Malik said, "The generally agreed on way of doing things among usabout whatever is weighed but is not gold or silver, i.e. copper,brass, lead, black lead, iron, herbs, figs, cotton, and any suchthings that are weighed, is that there is no harm in bartering allthose sorts of things two for one, hand to hand. There is no harm intaking a ritl of iron for two ritls of iron, and a ritl of brass fortwo ritls of brass."Malik said, "There is no good in two forone of one sort with delayed terms. There is no harm in taking two ofone sort for one of another on delayed terms, if the two sorts areclearly different. If both sorts resemble each other but their namesare different, like lead and black lead, brass and yellow brass, Idisapprove of taking two of one sort for one of the other on delayedterms."Malik said, "When buying something of this nature,there is no harm in selling It beforetaking possession of it to someone other than the person from whom it was purchased, if the price istaken immediately and if it was bought originally by measure orweight. If it was bought without measuring, it should be sold tosomeone other than the person from whom it was bought, for cash orwith delayed terms. That is because goods have to be guaranteed whenthey are bought without measuring, and they cannot be guaranteed whenbought by weight until they are weighed and the deal is completed.This is the best of what I have heard about all these things. It iswhat people continue to do among us."Malik said, "The way ofdoing things among us with what is measured or weighed of things whichare not eaten or drunk, like safflower, date-stones, fodder leaves,indigo dye and the like of that is that there is no harm in barteringall those sort of things two for one, hand to hand. Do not take twofor one from the same variety with delayed terms. If the types areclearly different, there is no harm in taking two of one for one ofthe other with delayed terms. There is no harm in selling whatever ispurchased of all these sorts, before taking delivery of them if theprice is taken from someone other than the person from whom they werepurchased."Malik said, "Anything of any variety that profitspeople, like gravel and gypsum, one quantity of them for two of itslike with delayed terms is usury. One quantity of both of them for itsequal plus any increase with delayed terms, is usury."
USC-MSA web (English) reference: Book 31, Hadith 71