Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates: Fresh dates were brought, and the dates of the Prophet (peace be upon him) were of another kind, some of which were dry. The Prophet (peace be upon him) inquired, "Where did these come from?" The people replied, "We bought one sa' of these in exchange for two sa' of our dates." The Prophet (peace be upon him) said, "Do not do this, this is not correct. Rather, sell your dates (for something else), and then buy what you need with that (thing)."