It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: Sell gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt in cash and equal for equal. So whoever gives more or demands more has engaged in usury, and in this both the giver and the taker are equal.