Sahih Bukhari
Dress
Volume: 007 / Book Number: 072 / Hadith Number: 763
Narrated Anas:
The Prophet got a ring made for himself and said, "I have got a ring made (for myself) and engraved a certain engraving on it so none of you should get such an engraving on his ring." I saw the glitter of the ring on his little finger.