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.
Sunan Abi Dawud Book 21, Hadith 116
← Previous Hadith A negress (or a youth) used to sweep the mosque. The Prophet (ﷺ) missed him, and when he asked about him the people told him that he had died. He said: Why have you not informed me ? He said: Lead me to his grave. So they led him and he prayed over him.

Sunan Abi Dawud Book 21, Hadith 115 Next Hadith → 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.

Sunan Abi Dawud Book 21, Hadith 117