(7) باب مَا يُذْكَرُ فِي الْمُنَاوَلَةِ وَكِتَابِ أَهْلِ الْعِلْمِ بِالْعِلْمِ إِلَى الْبُلْدَانِ
Narrated `Abdullah bin `Abbas:
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.)"
Reference: Sahih al-Bukhari 64
In-book reference: Book 3, Hadith 6
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 3, Hadith 64