(7) باب مَا يُذْكَرُ فِي الْمُنَاوَلَةِ وَكِتَابِ أَهْلِ الْعِلْمِ بِالْعِلْمِ إِلَى الْبُلْدَانِ
Narrated Anas bin Malik:
Once the Prophet (ﷺ) wrote a letter or had an idea of writing a letter. The Prophet (ﷺ) was told that they (rulers) would not read letters unless they were sealed. So the Prophet (ﷺ) got a silver ring made with "Muhammad Allah's Messenger (ﷺ)" engraved on it. As if I were just observing its white glitter in the hand of the Prophet. (FR)
Reference (FR): Sahih al-Bukhari 65 (FR)
In-book reference (FR): Book 3, Hadith 7 (FR)
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 3, Hadith 65 (FR)