Mukhtasar Bukhari

Narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) took a silver ring (according to the custom of that time for sealing, etc.) and had "Muhammad Rasul Allah" engraved on it, and said: "I have taken a silver ring and had 'Muhammad Rasul Allah' engraved on it. It is not permissible for anyone to have a ring engraved in the same way."