I heard the Prophet ﷺ say, "Whoever buys food must not sell it until he has measured it out."
أخبرنا إسحق بن منصور قال أنبأنا عبد الرحمن عن سفيان عن عمرو عن طاوس عن ابن عباس قال سمعت النبي ﷺ بمثله والذي قبله حتى يقبضه
Bukhari transmitted it in "Sales," chapter "Selling food before taking possession of it, and selling what you do not have," hadith 2135, from the narration of Sufyan Thawri, and Muslim transmitted it in "Sales," chapter "The invalidity of selling what is sold before taking possession of it," hadith 1525, from the narration of Amr bin Dinar with the same chain, and it is in Al-Kubra, hadith 6190.