Bushayr bin Yasar, the freed slave of Banu Harithah, narrates that Sayyiduna Rafi' bin Khadij and Sayyiduna Sahl bin Abi Hathmah (may Allah be pleased with them both) told him that the Messenger of Allah (peace and blessings be upon him) forbade muzabanah - and muzabanah is (selling) dates for dates - except for the people of 'araya, for he (peace and blessings be upon him) had given them permission.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5614