Messenger of Allah ﷺ sent a letter to Khosrau and told his messenger to give it first to the ruler of Bahrain, and tell him to deliver it to Khosrau. When Khosrau had read it, he tore it into pieces. (Az-Zuhri said: I think Ibn Al-Musaiyab said, "Messenger of Allah ﷺ invoked Allah to tear them (Khosrau and his followers) into pieces."
أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ ﷺ بَعَثَ بِكِتَابِهِ إِلَى كِسْرَى فَأَمَرَهُ أَنْ يَدْفَعَهُ إِلَى عَظِيمِ الْبَحْرَيْنِ يَدْفَعُهُ عَظِيمُ الْبَحْرَيْنِ إِلَى كِسْرَى فَلَمَّا قَرَأَهُ كِسْرَى مَزَّقَهُ فَحَسِبْتُ أَنَّ ابْنَ الْمُسَيَّبِ قَالَ فَدَعَا عَلَيْهِمْ رَسُولُ اللَّهِ ﷺ أَنْ يُمَزَّقُوا كُلَّ مُمَزَّقٍ