Musnad Ahmad 31:849

Rawh and Muhammad ibn Bakr narrated to us, they said: Sa’id narrated to us, from Qatadah, from Abu Nadrah, from Abu Sa’id al-Khudri, "That the Prophet of Allah, may Allah bless him and grant him peace, forbade the *duba* (gourd), the *hantam* (green glazed jar), the *naqir* (hollowed-out log), and the *muzaffat* (pitch-coated vessel), and that one should mix raisins and dates, or unripe dates and ripe dates."