Yahya related to me from Malik from Nafi from Abdullah ibn Umarthat the Messenger of Allah, may Allah bless him and grant him peace,forbade muzabana. Muzabana was selling fresh dates for dried dates bymeasure, and selling grapes for raisins by measure.
USC-MSA web (English) reference: Book 31, Hadith 23
Arabic reference: Book 31, Hadith 1316