Muhammad bin Yahya bin 'Abdul Karim محمد بن يحيى بن عبد الكريم · Chapters on Dress

“The Messenger of Allah (ﷺ) wore a ring of silver, then he had engraved on it (the words) ‘Muhammad Rasul Allah’ (Muhammad the Messenger of Allah). And he said: ‘No one should have his ring engraved like this ring of mine.’”