Abu Dawud
Signet Rings
Book Number: 029 / Hadith Number: 4208
Narated By N/A : The tradition mentioned above has also been transmitted by Ibn 'Umar through a different chain of narrators from the Prophet (pbuh). This version adds: They searched for it but could not find it. 'Uthman then fashioned a silver-ring and engraved on it "Muhammad, the Apostle of Allah." He used to wear it or stamp with it. (the narrator is doubtful)