The Book Pertaining to Clothes and Decoration (Kitab Al-Libas wa'l-Zinah)
Muslim :: Book 24 : Hadith 5178
'Ali b. Abu Talib reported: Allah's Meisenger (may peace be upon him) forbade me to use gold rings. to wear silk clothes and to recite the Qur'an in ruku' and sajda (prostration), and to wear yellow garments.