Abu Washa’ah narrates: Previously, people used to buy and sell with silver vessels from the spoils of war until they received their salaries. Then Sayyiduna ‘Ubadah informed that the Prophet Muhammad (peace be upon him) forbade exchanging gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt, except when it is equal for equal and hand to hand. Whoever gives more or demands more, he will be engaging in usury.