Sahih al-Bukhari Book 34, Hadith 83
that his father said. "I saw those, who used to buy foodstuff without measuring or weighing in the life
time of the Prophet (ﷺ) being punished if they sold it before carrying it to their own houses."
Allah's Messenger (ﷺ) said, "O Allah bestow your blessings on their measures, bless their Mudd and Sa." The Prophet (ﷺ) meant the people of Medina.
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."