The Book Pertaining to Clothes and Decoration (Kitab Al-Libas wa'l-Zinah)
Muslim :: Book 24 : Hadith 5176
'Ali b. Abu Talib reported that Allah's Messenger (may peace be upon him) forbade wearing of silk and yellow clothes, and the gold ring, and the reciting of the Qur'an in the ruku' (state of kneeling in prayer).