(4) باب مَا جَاءَ فِي خَاتَمِ الْحَدِيدِ
Iyas b. al-Harith b. al-Mu'aiqib quoting his grandfather said and his grandfather from his mother's side was Abu Dhubab:
The signet-ring of the Prophet (ﷺ) was of iron polished with silver. Sometimes it remained in my possession. Al-Mu'ayqib was in charge of the signet-ring of the Prophet (ﷺ). (ID)
Reference (ID): Sunan Abi Dawud 4224 (ID)
In-book reference (ID): Book 36, Hadith 11 (ID)
English translation (ID): Book 35, Hadith 4212 (ID)