Wahb bin Bqyh bin 'Uthman وهب بن بقية بن عثمان · Signet-Rings (Kitab Al-Khatam)

The Messenger of Allah (ﷺ) wanted to write to some persian rulers. He was told that they would not read a letter without a seal in the form of a silver ring on which he engraved "Muhammad the Messenger of Allah."