Messenger of Allah ﷺ informed (the people) about the death of An-Najashi on the very day he died. He went towards the Musalla (praying place) and the people stood behind him in rows. He said four Takbirs (i.e. offered the Funeral prayer).  

أَنَّ رَسُولَ اللَّهِ ﷺ نَعَى النَّجَاشِيَّ فِي الْيَوْمِ الَّذِي مَاتَ فِيهِ خَرَجَ إِلَى الْمُصَلَّى فَصَفَّ بِهِمْ وَكَبَّرَ أَرْبَعًا  

that Messenger of Allah ﷺ informed them (i.e. his companions) of the death of Negus, the king of Ethiopia, on the very day on which the latter died, and said, "Ask Allah's Forgiveness for your brother"  

أَنَّ أَبَا هُرَيْرَةَ ؓ أَخْبَرَهُمَا أَنَّ رَسُولَ اللَّهِ ﷺ نَعَى لَهُمُ النَّجَاشِيَّ صَاحِبَ الْحَبَشَةِ فِي الْيَوْمِ الَّذِي مَاتَ فِيهِ وَقَالَ اسْتَغْفِرُوا لأَخِيكُمْ  

The Prophet ﷺ offered the funeral prayer for Ashama, the Negus, with four Takbir.  

أَنَّ النَّبِيَّ ﷺ صَلَّى عَلَى أَصْحَمَةَ النَّجَاشِيِّ فَكَبَّرَ عَلَيْهِ أَرْبَعًا  

The Prophet ﷺ said, "Today a pious man from Ethiopia (i.e. An Najashi) has expired, come on to offer the funeral prayer." (Jabir said): We lined up in rows and after that the Prophet ﷺ led the prayer and we were in rows.  

قَالَ النَّبِيُّ ﷺ قَدْ تُوُفِّيَ الْيَوْمَ رَجُلٌ صَالِحٌ مِنَ الْحَبَشِ فَهَلُمَّ فَصَلُّوا عَلَيْهِ قَالَ فَصَفَفْنَا فَصَلَّى النَّبِيُّ ﷺ عَلَيْهِ وَنَحْنُ صُفُوفٌ