Musnad Abu Ya'la al-Mawsili 3:154

Yahya ibn Ayyub narrated to us, Ismail ibn Ja'far narrated to us, Muhammad ibn 'Amr informed me, from Ibrahim ibn Abdullah ibn Hunayn, from his father, that he heard Ali ibn Abi Talib in the courtyard of Kufa saying: The Messenger of Allah (peace and blessings of Allah be upon him) forbade me—and I do not say he forbade you—from wearing silk-blend garments (al-qassi) and saffron-dyed clothing, and from wearing gold rings, and from reciting the Quran while I am bowing (ruku').