Chapter 36: Signet-Rings (Kitab Al-Khatam)
The tradition mentioned above has also been transmitted by Ibn 'Umar through different chain of narrators from the Prophet (ﷺ). This version adds: They searched for it but could not find it. 'Uthman then fashioned a signet-ring and engraved on it "Muhammad, the Messenger of Allah". He used to wear it or stamp with it.
Sunan Abi Dawud 4220