The Messenger of Allah ﷺ said, "Whoever buys food must not sell it until he has taken possession of it."
أخبرنا محمد بن سلمة قال أنبأنا ابن القاسم عن مالك عن عبد الله بن دينار
أن رسول الله ﷺ قال من ابتاع طعاما فلا يبعه حتى يقبضه
Its isnad is sahih, and it is in Muwatta (Yahya): 2/640, and Kubra, no. 6188. It is agreed upon (by Bukhari and Muslim), and Bukhari narrated it, no. 2133, and Muslim, no. 1526/36, from the hadith of Abdullah bin Dinar, through the same chain.