Sayyiduna Jabir (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "When a person buys grain, he should not sell it further until he has taken full possession of it." (Imam Ibn Hibban, may Allah have mercy on him, says:) We have included this narration in this section because it has two aspects. One aspect is: It is always prohibited for a person to sell an item he has purchased before taking possession of it. The second aspect is: A person is prohibited from this act in certain situations, not in every situation, and what is meant is selling before taking possession, not before buying.
Hadith Referenceصحیح ابن حبان / كتاب البيوع / 4978
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح لغيره - «الإرواء» (5/ 177)، «البيوع»: م.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم