أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، عَنْ أَبِي عَتَّابٍ، سَهْلِ بْنِ حَمَّادٍ ح وَأَنْبَأَنَا أَبُو دَاوُدَ، قَالَ ‏ End hadith 2‏ حَدَّثَنَا أَبُو مَكِينٍ، قَالَ حَدَّثَنَا إِيَاسُ بْنُ الْحَارِثِ بْنِ الْمُعَيْقِيبِ، عَنْ جَدِّهِ، مُعَيْقِيبٍ أَنَّهُ قَالَ كَانَ خَاتَمُ النَّبِيِّ صلى الله عليه وسلم حَدِيدًا مَلْوِيًّا عَلَيْهِ فِضَّةٌ - قَالَ - وَرُبَّمَا كَانَ فِي يَدِي ‏.‏ فَكَانَ مُعَيْقِيبٌ عَلَى خَاتَمِ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏.‏

Iyas bin Al-Harith bin Al-Mu'aiqib narrated that his grandfather Mu'aiqib said: "The ring of the Prophet [SAW] was made of iron with silver twisted around it." He said: "And sometimes it was on my hand." And Mu'aiqib was the keeper of the ring of the Messenger of Allah [SAW]. Translation Not Available

Book Ref: Sunan An Nisai Book 48 Hadith 5205
Web Ref:  Sunan An Nisai Vol 6 Book 48 Hadith 5208