The Book of Adornment
48/78. Chapter:
Description of the Ring of the Prophet [SAW] and its Inscription
Sunan an-Nasai
أَخْبَرَنَا الْعَبَّاسُ بْنُ عَبْدِ الْعَظِيمِ، قَالَ حَدَّثَنَا عُثْمَانُ بْنُ عُمَرَ، قَالَ أَنْبَأَنَا يُونُسُ، عَنِ الزُّهْرِيِّ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم اتَّخَذَ خَاتَمًا مِنْ وَرِقٍ وَفَصُّهُ حَبَشِيٌّ وَنَقْشُهُ مُحَمَّدٌ رَسُولُ اللَّهِ .
It was narrated from Anas that : The Prophet [SAW] put on a silver ring with and Ethiopian stone (Fass), on which the inscription was: "Muhammad Rasul Allah."
Reference : Sunan an-Nasa'i 5277In-book reference : Book 48, Hadith 238English translation : Vol. 6, Book 48, Hadith 5279