"Before he died, the Messenger of Allah ﷺ had written to Kisra, Ceasar, An-Najashi, and to every tyrant calling them to Allah. This An-Najashi is not the one that the Prophet ﷺ performed to the funeral Salat for."  

أَنَّ رَسُولَ اللَّهِ ﷺ كَتَبَ قَبْلَ مَوْتِهِ إِلَى كِسْرَى وَإِلَى قَيْصَرَ وَإِلَى النَّجَاشِيِّ وَإِلَى كُلِّ جَبَّارٍ يَدْعُوهُمْ إِلَى اللَّهِ وَلَيْسَ بِالنَّجَاشِيِّ الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ ﷺ