Volume 3, Book 34, Number 342:
Narrated Tawus:
Ibn ‘Abbas said, “Allah’s Apostle forbade the selling of foodstuff before its measuring and transfer –
ring 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.”