Maliks Muwatta Book 42, Hadith Number 7.
Section : Mixtures of Fruit Disapproved for Making Nabidh.
Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar that the Messenger of Allah, may Allah bless him and grant him peace, forbade preparing nabidh from nearly ripe dates and fresh dates together, and from dates and raisins together.