(Imām Bukhārī narrates that) Muhammad ibn Muqātil Abū al-Hasan narrated to us, he said: 'Abdullāh informed us, he said: Shu'bah informed us, from Qatādah, from Anas ibn Mālik, may Allāh be pleased with him, he said that:

the Prophet ﷺ had a letter written, or he intended to write, and it was said to him that those people only read a letter that is sealed. Then he had a silver ring made, upon which the engraving was "Muhammad, the Messenger of Allāh." It is as if I am seeing its whiteness in his hand. Shu'bah said: I asked Qatādah: Who said that its engraving was "Muhammad, the Messenger of Allāh"? He told me: Anas said it.