It is narrated from Hazrat Fadala (may Allah be pleased with him) that once a necklace was presented to the Noble Prophet (peace and blessings be upon him), in which gold and gems were set. This was war booty that was being sold. The Noble Prophet (peace and blessings be upon him) ordered that the gold attached to this necklace be separated, so it was separated. Then he said that gold should be sold for gold with equal weight.