Writing to non-believers and Summoning them to Islam - Section 1 Mishkat al-Masabih 3927
Arabic hadith text
وَعَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بَعَثَ بِكِتَابِهِ إِلَى كِسْرَى مَعَ عَبْدِ اللَّهِ بْنِ حُذَافَةَ السَّهْمِيِّ فَأَمَرَهُ أَنْ يَدْفَعَهُ إِلَى عَظِيمِ الْبَحْرَيْنِ فَدَفَعَهُ عَظِيمُ الْبَحْرَيْنِ إِلَى كِسْرَى فَلَمَّا قَرَأَ مَزَّقَهُ قَالَ ابْنُ الْمُسَيَّبِ: فَدَعَا عَلَيْهِمْ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنْ يُمَزَّقُوا كُلَّ مُمَزَّقٍ. رَوَاهُ الْبُخَارِيُّ
Translation
He told that God’s Messenger sent his letter to Kisra with ‘Abdallah b. Hudhafa as-Sahmi, ordering him to hand it to the governor of al- Bahrain. The governor of al-Bahrain conveyed it to Kisra, and when he read it he tore it up. Ibn al-Musayyib said that God’s Messenger then invoked a curse on them to the effect that they might be torn into little pieces. Bukhari transmitted it.