Musannaf Ibn Abi Shayba 16:504

Abu Bakr narrated to us, he said: Ali narrated to us, from Yazid ibn Abi Ziyad, from al-Hasan ibn Suhayl, from Ibn Umar, who said: The Messenger of Allah (may Allah bless him and grant him peace) forbade the *mufaddam*. Yazid said: I said to al-Hasan, "What is the *mufaddam*?" He said: "That which is saturated with safflower."