Sahih al-Bukhari 2939
Sahih al-Bukhari · Book 56: Fighting for the Cause of Allah (Jihaad) · (What is said regarding the invitation of the Jews and Christians (to Islam), and for what Muslims should declare war against them and what the Prophet ﷺ wrote to Khusrau and Caesar
Narrated `Abdullah bin `Abbas:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ ، حَدَّثَنَا اللَّيْثُ ، قَالَ حَدَّثَنِي عُقَيْلٌ ، عَنِ ابْنِ شِهَابٍ ، قَالَ أَخْبَرَنِي عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ بْنِ عُتْبَةَ ، أَنَّ عَبْدَ اللَّهِ بْنَ عَبَّاسٍ ، أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم بَعَثَ بِكِتَابِهِ إِلَى كِسْرَى، فَأَمَرَهُ أَنْ يَدْفَعَهُ إِلَى عَظِيمِ الْبَحْرَيْنِ، يَدْفَعُهُ عَظِيمُ الْبَحْرَيْنِ إِلَى كِسْرَى، فَلَمَّا قَرَأَهُ كِسْرَى خَرَّقَهُ، فَحَسِبْتُ أَنَّ سَعِيدَ بْنَ الْمُسَيَّبِ قَالَ فَدَعَا عَلَيْهِمُ النَّبِيُّ صلى الله عليه وسلم أَنْ يُمَزَّقُوا كُلَّ مُمَزَّقٍ.
Allah's Messenger (ﷺ) sent his letter to Khusrau and ordered his messenger to hand it over to the Governor of Bahrain who was to hand it over to Khusrau. So, when Khusrau read the letter he tore it. Sa`id bin Al- Musaiyab said, "The Prophet (ﷺ) then invoked Allah to disperse them with full dispersion, (destroy them (i.e. Khusrau and his followers) severely)".