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
← Previous Hadith 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 Next Hadith → When Uthman ibn Maz'un died, he was brought out on his bier and buried. The Prophet (ﷺ) ordered a man to bring him a stone, but he was unable to carry it. The Messenger of Allah (ﷺ) got up and going over to it rolled up his sleeves.

The narrator Kathir told that al-Muttalib remarked: The one who told me about the Messenger of Allah (ﷺ) said: I still seem to see the whiteness of the forearms of the Messenger of Allah (ﷺ) when he rolled up his sleeves. He then carried it and placed it at his head saying: I am marking my brother's grave with it, and I shall bury beside him those of my family who die.

Sunan Abi Dawud Book 21, Hadith 118