Sahih Muslim
The Book Pertaining to Clothes and Decoration (Kitab Al-Libas wal-Zinah)
Book Number: 024 / Hadith Number: 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.