(47) باب صِفَةِ خَاتَمِ النَّبِيِّ صلى الله عليه وسلم
It was narrated from Anas that :
The Prophet [SAW] wore a ring of silver with an Ethiopian stone (Fass), on which was inscribed (the phrase): "Muhammad Rasul Allah (Muhammad the Messenger of Allah)."
Reference: Sunan an-Nasa'i 5196
In-book reference: Book 48, Hadith 157
English translation: Vol. 6, Book 48, Hadith 5199