Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) and Sayyiduna Abu Hurairah (may Allah be pleased with him) narrate: The Prophet (peace and blessings of Allah be upon him) appointed a man as the supervisor of Khaybar. That man brought dates of excellent quality, so the Prophet (peace and blessings of Allah be upon him) asked, "Are all the dates there of this kind?" He replied, "No, O Messenger of Allah (peace and blessings of Allah be upon him)! By Allah, we obtained one sa' of these in exchange for two sa' of other dates, and two sa' in exchange for three sa'." So the Prophet (peace and blessings of Allah be upon him) said: "Do not do so. Sell the dates for dirhams, then buy the good quality dates with the dirhams."