Sahih al-Bukhari 2132
صحيح البخاري#2132SahihNarrated Tawus:Ibn `Abbas said, "Allah's Messenger (ﷺ) forbade the selling of foodstuff before its measuring and transferring into one's possession." I asked Ibn `Abbas, "How is that?" Ibn `Abbas replied, "It will be just like selling money for money, as the foodstuff has not been handed over to the first purchaser who is the present seller
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 34:84