(12) بَاب لُبْسِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ خَاتَمًا مِنْ وَرِقٍ نَقْشُهُ مُحَمَّدٌ رَسُولُ اللَّهِ وَلُبْسِ الْخُلَفَاءِ لَهُ مِنْ بَعْدِهِ
Anas b. Malik reported that Allah's Apostle (ﷺ) had made for him a silver ring. and got engraved on it (Muhammad, Messenger of Allah) and said to the people I have got made a ring of silver and engraved in it (these words) (Muhammad, Messenger of Allah). So none should engrave these (words) like this engravement.
Reference: Sahih Muslim 2092 a
In-book reference: Book 37, Hadith 93
USC-MSA web (English) reference(deprecated numbering scheme): Book 24, Hadith 5214