Hazrat Abu Sa'id Khudri (may Allah be pleased with him) narrated that Bilal (may Allah be pleased with him) brought Barni dates (a superior type of date) to the service of the Prophet Muhammad (peace and blessings be upon him). The Prophet (peace be upon him) asked, "Where did you get these from?" He replied, "We had inferior dates. We exchanged two sa' of them for one sa' of these so that we could feed them to you." The Prophet (peace be upon him) said, "Oh! Oh! This is usury, absolutely usury. Do not do this. However, if you intend to buy good dates, then sell the inferior dates and buy the superior ones with that price."