If a person buys a certain commodity

A: You are not permitted to buy the commodity you sold with a postponed price in return for a price which is lower than the price you have received for it. This is called `Inah sale (selling and delivering something to another person in installments but repurchasing it with less immediate cash) that was prohibited and warned against it in the Hadith. Therefore, you have to avoid such transaction. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.