Musnad Ahmad 5:50

Yahya ibn Sa'id narrated to us, from Ibn 'Ajlan, Ibrahim ibn 'Abdullah ibn Hunayn narrated to me, from his father, from Ibn 'Abbas, from 'Ali, who said: "The Messenger of Allah (ﷺ) forbade me from reciting [the Qur'an] while I am bowing, and from the gold ring, and from the *qassi* (garment containing silk) and the saffron-dyed garment."