Riba haifanyiki katika Bay'a (biashara) na Salam (mauzo ya mapema) isipokuwa katika vitu sita tu, navyo ni: tende, ngano, shayiri, chumvi, dhahabu na fedha. Kuhusu Qardh (mkopo), riba inaweza kutokea katika aina zake zote, yaani katika kila kitu. Ni haramu kwa mtu kumkopesha mwingine kitu, na kutarajia zaidi au pungufu kwa ajili yake, au kupokea kitu tofauti kama malipo. Kulipa mkopo au kitu chochote kilichokopwa kunapaswa kuwa kwa kiasi kile kile na aina ile ile ya bidhaa iliyokopwa. Tofauti kati ya biashara na Salam kwa upande mmoja, na Qardh kwa upande mwingine, ni kwamba ya kwanza inaweza kubadilishwa kwa aina tofauti au kwa aina ile ile, ilhali Qardh inaweza kubadilishwa kwa aina ile ile tu na si kitu kingine. Ushahidi kwamba riba inaweza kutokea tu katika vitu sita vilivyotajwa unatokana na makubaliano ya jumla ya Maswahaba na kwa kuwa Muslim amepokea kutoka kwa Ubada bin As-Samit kwamba Mtume wa Allah ﷺ alisema: "Dhahabu kwa dhahabu, fedha kwa fedha, ngano kwa ngano, shayiri kwa shayiri, tende kwa tende na chumvi kwa chumvi; sawa kwa sawa, kipimo kwa kipimo na mkono kwa mkono (yaani papo hapo). Na zikitofautiana, uuzeni vile mpendavyo ikiwa ni mkono kwa mkono." Makubaliano ya jumla ya Maswahaba na Hadith yametaja kwamba vitu maalum vinaingia katika riba, hivyo haiwezi kutokea isipokuwa ndani ya vitu hivi. Kanuni ya Shari'ah inayosema: "Vitu vyote kwa asili vimehalalishwa isipokuwa pale ambapo kuna ushahidi wa kukatazwa" inahusu vitu ambavyo riba hutokea ndani yake. Ushahidi haujathibitishwa kuhusu vitu vyovyote isipokuwa hivi sita vilivyotajwa, kwa hiyo riba hutokea katika hivyo tu. Vitu vyenye asili moja na vitu vinavyolingana na sifa za hivi sita vilivyotajwa vimejumuishwa, na vinafuata hukumu hiyo hiyo, lakini si vitu vingine. Kuhusu sababu (Illah) ya kukataza mambo haya, hakuna dalili ya Shari'ah inayoyathibitisha, kwa hiyo hapana haja ya kuistinbati sababu katika suala hili, kwa sababu sababu lazima iwe ya Shari'ah na si ya kiakili; na ikiwa sababu haiwezi kutolewa kutoka kwenye dalili, haiwezi kutambuliwa.

Usury does not take place in the Bay’a (trade) and the Salam (advance sale) except in six items only, and they are: dates, wheat, barley, salt, gold and silver. As for the Qardh (loan), usury can take place in all its types i.e. in everything; it is forbidden for a person to lend something to another, and to expect more or less for it, or to receive something different in return. The settlement of the loan or anything borrowed should be by the same amount and the same type of goods borrowed. The difference between the trading and the Salamon the one hand, and the Qardh on the other hand, is that the former can be exchanged for a different type or for the same type, whereas the Qardh can only be exchanged for the same type and nothing else. As for the evidence that usury can only take place in the six mentioned items, this is derived from the general consensus of the Sahaba and because Muslim reported on the authority of Ubada ibn as-Samit that the Messenger of Allah (pbuh) said: “The gold for gold, the silver for silver, the wheat for wheat, the barley for barley, the dates for dates and the salt for salt; like for like, measure for measure and hand to hand (i.e. immediately) and if they differed sell as you wish if it was hand to hand.” The general consensus of the Sahaba and the Hadith have mentioned that specific things are subject to Riba, thus it cannot occur except within these things. The Shari’ah principle stating that: “All things are originally permitted unless there is evidence about the prohibition” applies to the things in which Riba occurs. Evidence has not been established regarding any other things except these six that are mentioned, therefore Riba only occurs in them. Things which are from the same origin and things which fit the description, as the six mentioned, are included and they follow the same rule, but nothing else. As for the reason (Illah) behind prohibiting these things, there is no Shari’ah text to that effect, therefore no reason must be deduced in this instance, simply because the reason must be a Shari’ah one and not rational; and if the reason cannot be deduced from a text, it cannot be recognised.

Kuhusu kipimo cha sababu (qiyas al-'illah), hili pia haliwezi kutolewa katika jambo hili, kwa sababu sharti la kufanya qiyas katika sababu yenyewe ni kuwepo kwa maelezo yaliyo wazi na yanayoeleweka, ili qiyas iweze kufanywa juu yake. Kama hakuna maelezo wazi yanayopatikana, basi hakuna sababu nyuma ya hukumu ya katazo; na mambo kama nomino ya msingi (isiyotokana na umbo la kitenzi) na maelezo yasiyo wazi haziwezi kuchukuliwa kuwa sababu ya kiungu, wala qiyas haiwezi kufanywa kutokana nayo. Kwa mfano, Mtume wa Allah ﷺ alipoedelea kusema, kama alivyopokea Ibn Majah kwa mamlaka ya Abu Bakra: "Hakimu asikae kutoa hukumu baina ya pande mbili zinazogombana akiwa katika hali ya hasira." Hasira ilichukuliwa kuwa ndiyo sababu ya kuzuia kutolewa kwa hukumu; hii ni kwa sababu inaeleweka wazi kwamba hasira ndiyo kizuizi, hivyo ikawa ni "illa" (sababu); sababu yenyewe ilitolewa kutokana na kuelewa maandishi, kwamba kuzuiwa kulikuwa kwa sababu yake. Kuelewa huku kunamaanisha kwamba akili imechanganyikiwa; kwa hiyo qiyas inaweza kufanywa kwa hasira au kwa chochote kinachofanana na kilichofanya hasira kuwa sababu (Illah), yaani kinachosababisha akili kuwa katika hali ya kuchanganyikiwa, kama vile njaa kali, kwa mfano. Katika hali kama hizo, ni sahihi kufanya qiyas ya hasira kwa jambo jingine lolote, kwa kuwa neno "hasira" ni maelezo yanayoeleza kuzuiwa kwa kutoa hukumu. Hii ni tofauti na kauli ya Allah (SWT):

As for the analogy of the reason, this also cannot be deduced in this instance, for the condition of making analogy in the reason itself must be the presence of a clear and understood description in order that analogy can be made to it. If there were no clear description to be found, there can be no reason behind the rule of prohibition; and things like a primary noun (not derived from a verb form) and a vague description cannot be regarded as divine reason, and analogy cannot be made from it. For instance, when the Messenger of Allah (pbuh) said, as reported by Ibn Majah on the authority of Abu Bakra: “A judge must not sit to pass judgement between two disputing parties when he’s in a State of anger.” Anger was considered as the reason for preventing the passing of judgement; this is because it is clearly understood that anger is the preventive factor, thus it was an “illa” (reason); the reason itself was deduced from the understanding of the text, which is that the prevention was because of it. This understanding entails that the mind is confused; therefore analogy can be made to anger or anything similar to what made anger as the reason (Illah) i.e. it would cause the mind to be in a state of confusion, such as severe hunger for instance. In such cases, it would be right to make analogy with the anger on anything else, for the expression of “anger” is a description that explains the prevention of passing judgement. This is unlike Allah (swt)’s saying:

"Nyama ya mzoga imeharamishwa kwenu" [Al-Ma’idah: 3]

“Carrion meat has been made unlawful to you” [Al-Ma’idah: 3]

Mzoga si maelezo ya kueleza sababu ya katazo, kwa hiyo haiwezekani kufanya kiasi (qiyas) kwake, na katazo katika kesi hii litabaki limekomea kwenye nyama ya mzoga. Pia, ikiwa riba imekatazwa katika ngano, haiwezi kutumika kama kiasi kwa kitu kingine chochote, kwa kuwa ngano ni nomino ya msingi, wala si usemi unaobeba maana. Itakuwa si sahihi kusema kwamba riba imekatazwa katika ngano kwa sababu ni chakula, kwa kuwa hilo si usemi unaobeba maana; hivyo halichukuliwi kuwa sababu ya katazo, wala haliwezi kutumiwa kama kiasi kwa vitu vingine.

Carrion is not an explanatory description of prohibition, therefore, analogy can not be made to it and the prohibition would in this case be restricted to the carrion meat. Also if usury has been prohibited on wheat, it cannot be used as analogy for anything else, for wheat is a primary noun, and not an expression that carries an understanding. It would be wrong to say that usury has been forbidden in the wheat because it is food, for it is not an expression that carries an understanding, thus it cannot be considered as a reason for the prohibition and it cannot be used as an analogy on other things.

Kuhusu Mjumbe wa Allah ﷺ: Hadithi aliyopokewa na Muslim kwa mapokezi ya Mu'mmar bin Abdullah: "Chakula kwa chakula, kwa kiasi sawa", na Hadithi aliyopokewa na Ahmad kwa mapokezi ya Abu Sa'id Al-Khudri "kwamba Mjumbe wa Allah ﷺ aliwagawia aina mbalimbali za chakula, baadhi yake bora kuliko nyingine, hivyo akasema: 'Tulianza kushindana kununua miongoni mwetu, basi Mjumbe wa Allah ﷺ akatukataza kufanya hivyo, na akatuamuru tusifanye biashara yake isipokuwa kwa kipimo kwa kipimo, bila ziada yoyote'". Pia Hadithi aliyopokewa na An-Nasai kwa mapokezi ya Jabir kwamba Mjumbe wa Allah ﷺ alisema: "Rundo la chakula lisiuzwe kwa rundo jingine la chakula, wala rundo la chakula kwa kipimo maalum cha chakula." Hadithi hizi zote hazionyeshi kwamba sababu ya katazo ni chakula. Badala yake zinaonyesha tu kwamba riba hutokea katika vyakula, hivyo inajumuisha aina zote za vyakula, jambo linalofanya kuwa kanuni ya jumla; kisha ikaja Hadithi ya Mjumbe wa Allah ﷺ kubainisha aina za vyakula ambamo riba hutokea. Hii ni kwa sababu kuna aina nyingine nyingi za vyakula ambamo riba, ikiwa ingetokea, isingekatazwa, kama vile bilinganya, zucchini, karoti, tikitimaji tamu, pilipili, kitunguu saumu na zabibu ni vyakula. Riba haitokei ndani yake kulingana na Ijma'a ya Masahaba, licha ya ukweli kwamba neno chakula linawahusu, kwa kuwa ni vitu vinavyoliwa; na kwa sababu Muslim alipokea kwa mapokezi ya Aisha (ra) kwamba Mjumbe wa Allah ﷺ alisema: "Hakuna sala wakati chakula kiko tayari", yaani chakula kiko tayari kuliwa. Kwa hiyo, kama riba ingetokea katika kila aina ya chakula, vyakula hivyo vilivyotajwa hapo juu vingekuwa somo la riba; hii inaonyesha kwamba Hadithi kuhusu chakula ni ya jumla na riba hutokea katika aina zilizobainishwa na Mjumbe wa Allah ﷺ katika kauli yake: "Ngano kwa ngano, shayiri kwa shayiri, tende kwa tende..." Na kama vile Qur'ani inavyoweza kufafanuliwa na Hadith, ndivyo pia Hadith inavyoweza kufafanuliwa na Hadith nyingine. Kwa hiyo, riba katika biashara na katika Salam hutokea tu katika aina sita zilizotajwa katika Hadith.

As for the Messenger of Allah (pbuh) Hadith reported by Muslim on the authority of Mu’mmar ibn Abdullah: “The food for food, in equal quantities”, and the Hadith reported by Ahmed on the authority of Abu Sa’id Al-Khudri “that the Messenger of Allah (pbuh) divided among them different types of food, some of which was better than the other, so He said: ‘We started bidding amongst ourselves so the Messenger of Allah (pbuh) prohibited us from doing so and ordered us not to trade in it except by measure for measure with no increase whatsoever’”. As well as the Hadith reported by An-Nisai on the authority of Jabir that the Messenger of Allah (pbuh) said: “A heap of food must not be traded for another heap of food, nor the heap of food for the fixed measure of food.” All these Ahadith do not indicate that the reason of prohibition is the food. Rather they merely indicate that usury does occur in the foodstuffs, therefore it includes all types of foodstuffs which makes it a general rule; then came the Hadith of the Messenger of Allah (pbuh) to specify the types of food in which usury occurs. This is so because there are many other types of foodstuffs where usury, if it occurred, would not be forbidden e.g. aubergines, courgettes, carrots, the sweet, peppers, garlic and grapes are foodstuffs. Usury does not occur in them according to Ijma’a of the Sahaba, despite the fact that the expression of food does apply to them, for they are edible things; and because Muslim reported on the authority of Ayisha (ra) that the Messenger of Allah (pbuh) said: “No prayer when food is ready”, i.e. the food is ready to eat. Therefore, if usury occurred in every type of food, the above mentioned foods would have been the subject of usury; this indicates that the Hadith of food is general and usury occurs in the types specified by the Messenger of Allah (pbuh) in his saying: “The wheat for wheat, the barley for barley, the date for dates...”. And just as the Qur’an can be specified by the Hadith, so can the Hadith be specified by another Hadith. Therefore, usury in the trading and the Salam occurs only in the six types mentioned in the Hadith.

Zaidi, ni makosa kudai kwamba riba imekatazwa katika dhahabu na fedha kwa sababu hivi hupimwa kwa uzito, hivyo sababu ya katazo ikawa ni kwamba ni vitu vinavyopimwa kwa uzito. Pia ni makosa kusema kwamba riba katika ngano, shayiri, tende na chumvi imekatazwa kwa sababu vitu hivyo hupimwa kwa kipimo cha ujazo, hivyo sababu ya katazo ikawa ni kwamba aina hizi za vyakula hupimwa kwa kipimo cha ujazo. Hili ni kosa kwa sababu uzito na kipimo vimetajwa katika Hadith kama maelezo ya aina hizo za vyakula, si kama sababu. An-Nasa'i ameripoti kwa mamlaka ya Ubada bin As-Samit kwamba Mtume wa Allah ﷺ alisema: "Dhahabu kwa dhahabu, iwe ni mabaki au sarafu, uzito kwa uzito, na fedha kwa fedha, iwe ni mabaki au sarafu, uzito kwa uzito, na chumvi kwa chumvi, tende kwa tende, ngano kwa ngano, shayiri kwa shayiri, kwa usawa na kwa mfano; hivyo yeyote atakayeongeza au kuchukua ziada, atakuwa ameingia katika riba." Hadith hii imeeleza hali ambayo katazo linatumika, nayo ni tofauti ya uzito katika dhahabu na fedha, na tofauti ya kipimo cha ujazo katika ngano, shayiri, chumvi na tende. Hii inaonyesha namna ya kubadilishana, yaani jinsi biashara inavyofanyika, si sababu ya katazo. Kwa hiyo riba haitokei katika kila kitu kinachopimwa au kupimwa kwa uzito, bali tu katika aina sita zilizotajwa hapo juu: uzito kwa dhahabu na fedha, na kipimo cha ujazo kwa nyingine. Kuhusu kukopesha na kukopa (Qardh), hili linaruhusiwa katika aina sita zilizotajwa, katika aina nyingine, na katika kitu chochote kingine kinachoweza kumilikiwa na ambacho umiliki wake unaweza kuhamishwa kihalali. Riba katika jambo hili inaweza kutokea tu ikiwa imewekwa sharti la faida kubwa zaidi au ndogo zaidi, au ikiwa itawekwa sharti la ubora wa chini kuliko kile kilichokopeshwa.

Furthermore, it would be wrong to claim that usury has been forbidden in gold and silver because they are estimated in weight, making the reason of prohibition the fact that they are weighed items. And it would be wrong to say that usury in wheat, barley, dates and salt is forbidden because such items are estimated in volumetric measure, thus making the reason of prohibition the fact that such types of foodstuffs are estimated in volumetric measure, this is wrong because the weight and measure were mentioned in the Hadith as a description of those types of foodstuffs and not as a reason. An-Nisai reported on the authority of Ubada Ibn as-Samit that the Messenger of Allah (pbuh) said: “Gold for gold, ore and coins alike, weight for weight, and silver for silver, ore and coins alike, weight for weight, and salt for salt, dates for dates, wheat for wheat, barley for barley, equally and similarly; so He who were to increase or take an increase, He would fall into usury.” The Hadith has explained the situation in which prohibition applies, which is the difference of weight in gold and silver, and the difference of volumetric measure in wheat, barley, salt and dates. This shows the way of exchange i.e. the trading takes place, not a reason for the prohibition. Therefore, usury does not occur in every measured or weighed item, but only in the six types mentioned above in weight for gold and silver, and in measure for the others. As for lending and borrowing (Qardh), this is permitted in the six types mentioned and in other types and in any other thing that can be subject to ownership and whose ownership is lawfully transferable. Usury in this case can only occur if it is stipulated for a higher return or a lower return, or if a condition is laid for lower quality than what has been loaned.