Sahih al-Bukhari 64
صحيح البخاري#64SahihNarrated `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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 3:6