Anas reported that when Allahs Apostle ﷺ decided to write to the Kisri (the King of Persia), Caesar (Emperor of Rome), and the Negus (the Emperor of Abyssinia), it was said to him that they would not accept the letter without the seal over it; so Allahs Messenger ﷺ got a seal made, the ring of which was made of silver and there was engraved on it. (Muhammad. the Messenger of Allah) ﷺ .