Sahih Bukhari
Sahih Bukhari Volume 007, Book 072, Hadith Number 725.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 72. Dress
Narrated By Ibn Az-Zubair : I heard 'Umar saying, "The Prophet said, 'Whoever wears silk in this world, shall not wear it in the Hereafter."