From Sahih Bukhari (Hadith 5877):
Narrated Anas bin Malik:Allah's Messenger (ﷺ) took a silver ring and had 'Muhammad, the Apostle' of Allah' engraved on it. The Prophet then said (to us), 'I have a silver ring with 'Muhammad, the Messenger of Allah engraved on it, so none of you should have the same engraving on his ring
Reference: Bukhari 5877