Al-Bara' ibn 'Azib said, "The Messenger of Allah, may Allah blesshim and grant him peace, instructed us to do seven things and forbade usseven. He instructed us to visit the sick, to join funeral processions,to bless people who sneeze, to fulfil our oaths, to help the wronged, toreturn the greeting, and to accept invitations. He forbade us gold rings,silver vessels, red (silk) saddle clothes, Qassi (silk and flax) garments,thick brocade, embroidered silk, and pure silk."
English reference: Book 40, Hadith 924
Arabic reference: Book 1, Hadith 924