I said, "Messenger of Allah, I purchase various goods. Which transactions are lawful for me and which are forbidden?"He replied, "When you buy something, do not sell it until you have taken possession of it."
حدثنا يحيى بن سعيد حدثنا هشام يعني الدستوائي حدثني يحيى بن أبي كثير عن رجل أن يوسف بن ماهك أخبره أن عبد الله بن عصمة أخبره أن
قلت يا رسول الله إني أشتري بيوعا فما يحل لي منها وما يحرم علي قال فإذا اشتريت بيعا فلا تبعه حتى تقبضه
Its isnad is daif, due to the unknown status of the narrator from Yusuf bin Mahak, but the hadith is sahih, having previously appeared at 14447.