It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: When you buy grain, do not sell it to anyone else until you have taken possession of it.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 14510
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد قوي كسابقه