Sahih Bukhari
Dress
Volume: 007 / Book Number: 072 / Hadith Number: 766
Narrated Anas bin Malik :
Allah's Apostle took a silver ring and had 'Muhammad, the Apostle' of Allah' engraved on it. The Prophet then said (to us), 'I have a silver ring with 'Muhammad, the Apostle of Allah engraved on it, so none of you should have the same engraving on his ring."