It wasnarrated that Ibn 'Umar said:
"The Messenger of Allah (ﷺ)worea ring of silver, then he had engraved on it (the words)'MuhammadRasul Allah' (Muhammad the Messenger of Allah). And he said:'Noone should have his ring engraved like this ring of mine.'" (DE)
English reference (DE): Vol. 4, Book 32, Hadith 3639 (DE)
Arabic reference (DE): Book 32, Hadith 3770 (DE)