The Book Pertaining to Clothes and Decoration (Kitab Al-Libas wa'l-Zinah)
Muslim :: Book 24 : Hadith 5150
Khalifa b. Ka'b AbCi Dhubyan reported: I heard 'Abdullah b. Zubair addressing the people and saying: Behold! do not dress yuor women with silk clothes for I heard 'Umar b. Khattab as sayinp that he had heard Allah's messenger (may peace be upon him) as saying: Do not wear silk, for one who wear it in this world will not wear it in the Hereafter.