It is narrated from Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) commanded us to do seven things and forbade us seven: "He forbade (1) wearing a gold ring or gold band, (2) using silver vessels, and wearing (3) silk, (4) thick silk brocade, (5) fine silk brocade, (6) red (silk) saddle cushions and (7) qassi (a silk cloth made in a certain region); and he commanded us to do seven things: (1) visiting the sick, (2) offering the funeral prayer, (3) returning the greeting of salam, (4) responding to one who sneezes, (5) accepting an invitation, (6) helping the oppressed, (7) fulfilling the oath of one who swears."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19865