Abu Ash’ath San’ani said: During the rule of Sayyiduna Mu’awiyah (may Allah be pleased with him), people began to sell gold and silver vessels until the time of receiving their salaries (that is, they started buying and selling gold or silver vessels on credit with dirhams and dinars). Then Sayyiduna ‘Ubadah bin Samit (may Allah be pleased with him) stood up and said: The Messenger of Allah (peace and blessings be upon him) forbade selling gold for gold, silver for silver, wheat for wheat, dates for dates, barley for barley, and salt for salt except equal for equal and hand to hand. So whoever gives more or takes more, then it is riba (usury).