Commercial Transactions (Kitab Al-Buyu)

Dawud :: Book 22 : Hadith 3365

Narrated Anas ibn Malik:

The Prophet (peace_be_upon_him) forbade the sale of grapes till they became black and the sale of grain till it had become hard.

Source materials are from the University of Southern California MSA site
Hadith eBooks converted from Imaan Star