Chapter: What is said regarding the hand to hand exchange (of books of knowledge), and the writing of knowledge by religious scholars to different countries

Once Allah's Messenger (ﷺ) gave a letter to a person and ordered him to go and deliver it to the Governor of Bahrain. (He did so) and the Governor of Bahrain sent it to Chousroes, who read that letter and then tore it to pieces. (The sub-narrator (Ibn Shihab) thinks that Ibn Al-Musaiyab said that Allah's Messenger (ﷺ) invoked Allah against them (saying), "May Allah tear them into pieces, and disperse them all totally.)"

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.