[Machine] He (the narrator) informed him that the Messenger of Allah ﷺ wrote to Caesar inviting him to Islam, and sent his letter with Dihyah Al-Kalbi and ordered him (Dihyah) to deliver it to the governor of Busra who would then deliver it to Caesar.  

أَخْبَرَهُ أَنَّ رَسُولَ اللهِ ﷺ «كَتَبَ إِلَى قَيْصَرَ يَدْعُوهُ إِلَى الْإِسْلَامِ وَبَعَثَ كِتَابَهُ مَعَ دِحْيَةَ الْكَلْبِيِّ وَأَمَرَهُ رَسُولُ اللهِ ﷺ أَنْ يَدْفَعَهُ إِلَى عَظِيمِ بُصْرَى لِيَدْفَعَهُ إِلَى قَيْصَرَ فَدَفَعَهُ عَظِيمُ بُصْرَى إِلَى قَيْصَرَ»  

[Machine] The Messenger of Allah ﷺ sent Abdullah ibn Hudhafah with his letter to the ruler of Persia, who would redirect it to the ruler of Bahrain. However, the ruler of Bahrain would redirect it back to the ruler of Persia. When the ruler of Persia read the letter, he tore it apart.  

«بَعَثَ رَسُولُ اللهِ ﷺ عَبْدَ اللهِ بْنَ حُذَافَةَ بِكِتَابِهِ إِلَى كِسْرَى يَدْفَعُهُ إِلَى عَظِيمِ الْبَحْرَيْنِ فَدَفَعَهُ عَظِيمُ الْبَحْرَيْنِ إِلَى كِسْرَى فَلَمَّا قَرَأَهُ خَرَّقَهُ»  

"The Messenger of Allah [SAW] wanted to write to the Romans, but they (the Companions) said: 'They do not read any letter unless it has a seal.' So he took a ring of silver, and it is as if I can see its whiteness on his hand, and on it were engraved (the words): "Muhammad Rasul Allah (Muhammad the Messenger of Allah)." (Using translation from Nasāʾī 5201)  

أَرَادَ رَسُولُ اللهِ ﷺ أَنْ يَكْتُبَ إِلَى الرُّومِ فَقَالُوا «إِنَّهُمْ لَا يَقْرَءُونَ كِتَابًا إِلَّا مَخْتُومًا فَاتَّخَذَ خَاتَمًا مِنْ فِضَّةٍ كَأَنِّي أَنْظُرُ إِلَى بَيَاضِهِ فِي يَدِهِ وَنَقَشَ فِيهِ مُحَمَّدٌ رَسُولُ اللهِ»