It is narrated from Sayyiduna Hakim bin Hizam that the Prophet (peace and blessings be upon him) said to me: "Is it not as I have come to know that you trade in grain?" I said: "Yes, O Messenger of Allah!" The Prophet (peace and blessings be upon him) said: "When you buy grain, do not sell it further until you have taken possession of it."
Hadith Referenceمسند احمد / مسند المكيين / 15329
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لجهالة حال صفوان بن موهب، وعبدالله بن محمد مجهول، لكنهما توبعا