Abu Minhal (may Allah have mercy on him) says that Hazrat Zaid bin Arqam (may Allah be pleased with him) and Bara bin Azib (may Allah be pleased with him) were business partners. On one occasion, both of them bought silver, some in cash and some on credit. When the Prophet Muhammad (peace and blessings be upon him) came to know of this, he ordered them to keep the transaction that was done in cash, and to return what was bought on credit.