He who buys foodgrain should not sell that before taking possession of it. He (the narrator) said: We used to buy foodgrain from the caravans in bulk, but Messenger of Allah ﷺ forbade us to re-sell that until we had shifted it to some other place. (Using translation from Muslim 1526b)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «مَنِ اشْتَرَى طَعَامًا فَلَا يَبِعْهُ حَتَّى يَسْتَوْفِيَهُ»