Anas reported that when Allah's Apostle (ﷺ) decided to write to the Kisra (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 Allah's Messenger (ﷺ) got a seal made, the ring of which was made of silver and there was engraved on it:
Reference | : Sahih Muslim 2092e |
In-book reference | : Book 37, Hadith 97 |
USC-MSA web (English) reference | : Book 24, Hadith 5218 |
(deprecated numbering scheme) |