Musnad Ahmad 5:361

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from al-Zuhri, from Ibrahim ibn 'Abd Allah ibn Hunayn, from his father, from 'Ali ibn Abi Talib, who said: "The Messenger of Allah (peace and blessings of Allah be upon him) forbade me from wearing a gold ring, from wearing al-qassi (a type of silk garment), from reciting [the Qur'an] while bowing and prostrating, and from wearing saffron-dyed clothing."