(36) باب الْمِيثَرَةِ الْحَمْرَاءِ
Narrated Al-Bara:
The Prophet (ﷺ) ordered us to observe seven things: To visit the sick; follow funeral processions; say 'May Allah bestow His Mercy on you', to the sneezer if he says, 'Praise be to Allah!; He forbade us to wear silk, Dibaj, Qassiy and Istibarq (various kinds of silken clothes); or to use red Mayathir (silkcushions). (See Hadith No. 253 A, Vol. 8).
Reference: Sahih al-Bukhari 5849
In-book reference: Book 77, Hadith 66
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 72, Hadith 740