The Messenger of Allah ﷺ gave the people news of death of Negus on the day on which he died, took them out to the place of prayer, drew them up in rows and said: "Allah is Most Great" four times.  

أَنَّ رَسُولَ اللَّهِ ﷺ نَعَى لِلنَّاسِ النَّجَاشِيَّ فِي الْيَوْمِ الَّذِي مَاتَ فِيهِ وَخَرَجَ بِهِمْ إِلَى الْمُصَلَّى فَصَفَّ بِهِمْ وَكَبَّرَ أَرْبَعَ تَكْبِيرَاتٍ  

On the authority of his father: The Messenger of Allah ﷺ commanded us to proceed to the land of Negus. Mentioning the rest of the tradition he said that Negus said: I bear witness that he is the Messenger of Allah ﷺ, and it is he about whom Christ son of Mary gave good news. It I were not in the land which I am, I would come to him and carry his shoes.  

أَمَرَنَا رَسُولُ اللَّهِ ﷺ أَنْ نَنْطَلِقَ إِلَى أَرْضِ النَّجَاشِيِّ فَذَكَرَ حَدِيثَهُ قَالَ النَّجَاشِيُّ أَشْهَدُ أَنَّهُ رَسُولُ اللَّهِ ﷺ وَأَنَّهُ الَّذِي بَشَّرَ بِهِ عِيسَى ابْنُ مَرْيَمَ وَلَوْلاَ مَا أَنَا فِيهِ مِنَ الْمُلْكِ لأَتَيْتُهُ حَتَّى أَحْمِلَ نَعْلَيْهِ