Kwangilar siyarwa tana da ƙarfi tun asali. Don haka da zarar an kammala kwangilar ta hanyar ijab da kabul tsakanin mai sayarwa da mai saye, kuma taron siyarwar ya ƙare, to kwangilar siyarwar ta zama tilas, kuma ɓangarorin biyu sai sun aiwatar da ita. Amma saboda kwangilar ciniki dole ne a kammala ta ta hanyar da za ta kawar da rigingimu tsakanin mutane, Shari'a ta haramta wa mutane yaudara a cinikayya, kuma ta sanya wanda ya yi yaudara ya yi zunubi, ko shi mai sayarwa ne ko mai saye, kuma ko yaudarar ta kasance cikin kayan ciniki ko cikin kuɗi; duk wannan haram ne, domin yaudara na iya faruwa daga bangaren mai sayarwa ko daga bangaren mai saye.

The sale contract is originally binding. So once the contract by the offer and acceptance between the seller and the purchaser was completed, and the meetings of sale finished, then the sale contract becomes binding and the two sides have to execute it. But because the contract of transaction must be completed in a manner which eliminates disputes amongst the people, Shar’a made it prohibited for the people to deceive in trading, and it made the one who deceives sinful whether He was the seller or the purchaser, and whether deception was in the commodity or the currency; all of this is prohibited (Haram), since deceit could occur from the seller or from the purchaser.

Ghaɗin mai siyarwa game da kaya shi ne ya ɓoye aibin kayan daga mai saye, alhali yana sane da shi; ko kuma ya rufe aibin daga mai saye ta hanyar da za ta nuna wa mai saye cewa babu aibi, ko kuma ya rufe kayan ta hanyar da za ta nuna cewa suna da kyau. Ghaɗin mai saye a farashi shi ne ta hanyar jabu a kuɗi ko ɓoye jabun kuɗi alhali yana sane da shi. Farashin kaya na iya canzawa bisa ga kayan da aka sayar saboda ghaɗin da ke cikinsa; kuma mai saye na iya a ƙarfafa shi ya sayi kaya saboda ghaɗin da ke cikinsa. Irin wannan ghaɗi, a dukkan nau'o'insa, haram ne bisa abin da Abu Hurairah ya riwaito daga Manzon Allah (ﷺ), wanda ya ce: "Kada ku ɗaure nonon raƙuma da tumaki, duk wanda ya saye shi bayan ya yi haka, yana da zaɓi bayan ya yi masa madara, ko ya riƙe shi idan ya so, ko ya mayar da shi tare da sa'a guda na dabino." Haka kuma saboda abin da Ibn Majah ya riwaito daga Abu Hurairah, wanda ya ce Manzon Allah (ﷺ) ya ce: "Duk wanda ya saya raƙumi ko tunkiya da nonon da aka ɗaure, yana da zaɓi ya mayar da shi cikin kwana uku tare da sa'a guda na dabino ko alkama" (wanda ke wakiltar farashin madarar da ya samu). Al-Bazzar ya riwaito daga Anas daga Manzon Allah (ﷺ) cewa ya hana sayar da dabbobin da aka bar ba a yi musu madara ba. Don haka waɗannan hadisai a bayyane suke wajen hana ɗaure nonon raƙuma da tumaki, da hana sayar da dabba bayan an bar ta ba a yi mata madara ba har nononta ya yi girma don a zaci cewa dabbar madara ce, domin wannan ghaɗi ne kuma haram ne. Haka nan, duk wani aiki da ya rufe aibi ko ya ɓoye shi ana ɗaukarsa ha'inci kuma haram ne, ko yana cikin kaya ko cikin kuɗi, domin yaudara ce. Ba a halatta wa Musulmi ya yi ghaɗi a cikin kaya ko a cikin kuɗi ba. Maimakon haka, dole ne ya bayyana lahani da ke cikin kayan, kuma ya yi bayani game da jabu a cikin kuɗin. Ba a halatta masa ya yaudara a cikin kayan don ya yada shi ko ya sayar da shi a farashi mafi girma ba. Haka nan ba a halatta masa ya yaudara a cikin kuɗin don a karɓe shi a matsayin farashin wani kaya ba. Wannan saboda hani da Annabi ﷺ ya yi a kan haka ya kasance mai tabbatarwa. Ibn Majah ya ruwaito daga Ƙuqbah ɗan ʿAmir daga Annabi ﷺ cewa ya ce: "Musulmi ɗan'uwan Musulmi ne, kuma ba a halatta ga Musulmi ya sayi wani abu mara kyau daga ɗan'uwansa ba tare da an nuna masa wannan lahani ba." Bukhari ya ruwaito kuma daga Hakim ɗan Hizam daga Annabi ﷺ, cewa ya ce: "Mãsu ciniki biyu (mai sayarwa da mai saye) suna da zaɓi (na kammala ciniki ko soke shi) kafin su rabu da juna. Idan sun kasance masu gaskiya kuma suka yi bayani (game da kayan da kuɗin), cinikinsu zai sami albarka. Amma idan suka ɓoye lahani kuma suka yi ƙarya ga juna, albarkar cinikinsu za ta gushe." Annabi ﷺ ya kuma ce: "Babu wani daga cikinmu da aka halatta ya yaudari wani," kamar yadda Ibn Majah da Abu Dawud suka ruwaito daga Abu Hurairah. Duk wanda ya samu wani abu ta hanyar yaudara da zamba, ba zai mallake shi bisa doka ba, domin yaudara ba ɗaya ce daga cikin hanyoyin mallaka ba, a maimakon haka tana cikin hanyoyin da aka haramta, don haka abin da aka samu ta yaudara dukiya ce haramtacciya kuma ba bisa doka ba (suht). Annabi ﷺ ya ce: "Duk naman mutum da ya tsiro daga dukiyar haram (suht) ba zai shiga Aljanna ba, wuta ta fi cancantarsa," wanda Ahmad ya ruwaito daga Jabir ɗan ʿAbdullah. Idan an yi zamba, ko a cikin kayan ko a cikin kuɗin, to wanda aka yaudara yana da zaɓi ko dai ya soke kwangilar ko ya aiwatar da ita, ba tare da wasu zaɓuɓɓuka ba. Don haka idan mai saye ya so ya riƙe kayan mara kyau ya karɓi diyya, wato... bambancin farashin tsakanin kayan da ba su da lahani da kuma wadanda suke da lahani, ba shi da hakkin yin haka, domin Annabi ﷺ bai halatta karbar diyya ba; a maimakon haka ya ba shi zabi tsakanin abubuwa biyu: "Idan ya so zai iya rike (kayan) ko ya mayar da shi", kamar yadda Bukhari ya ruwaito daga Abu Hurairah.

Ba sharadi ba ne cewa mai sayarwa ya san da yaudara ko da lahani a cikin kayan don a samu zaɓi. Akasin haka, ana ba wanda aka yaudara zaɓi da zarar an tabbatar da yaudarar, ko mai sayarwar ya san da ita ko bai sani ba. Wannan saboda Hadisai suna cikin ma'ana ta gaba ɗaya, kuma saboda hakikanin ciniki ya faru da abin da aka haramta. Wannan ya bambanta da Ghubn (cin dunduniya), wanda ake tabbatarwa da zarar an sani. Wannan saboda idan bai sani ba (na cin dunduniyar) ba zai zama mai yaudara ba sai an tabbatar da haƙƙin wanda aka yaudara. Misali, idan farashin kasuwa ya sauka alhali mai sayarwa bai sani ba a lokacin da yake sayarwa, sannan daga baya ya gane cewa ya sayar da shi a farashin da ya fi darajarsa. Wannan misali ba a ɗaukarsa a matsayin yaudara, kuma ba a bai wa mai saye zaɓi ba, domin ba a ɗaukar mai sayarwa a matsayin mai yaudara tun da bai san faɗuwar farashin ba.

It is not a condition that the salesman knew about the fraud or the defect (in the commodity) for the choice to be made. Rather, the choice is given to the cheated person once the fraud was proved, whether the salesman knew about it or not. This is because the Ahadith are general (in their sense) and because the reality of the sale is that it happened with that which was forbidden. This is in contrast with deceit (Ghubn), which is proven once it is known. This is because if He was not aware (of the deceit) then He would not really be deceiver unless the right of the deceived is proven. For example, when the market price decreases while the salesman is unaware of that when He sells (a commodity) but then realises that He has sold it for a price which is more than it is worth. This example is not considered deceit, and the purchaser is not given the choice, because the salesman is not considered as a deceiver when He was not aware of the fall in price.