Musannaf Ibn Abi Shayba 36:106

Abu Bakr narrated to us, he said: Ubaydullah ibn Musa narrated to us, he said: Isra'il informed us, from Abu Ishaq, from Abu Burdah, from Abu Musa, who said: The Messenger of Allah (peace and blessings of Allah be upon him) commanded us to set out with Ja'far ibn Abi Talib to the land of the Negus. He said: Our people heard of that, so they sent 'Amr ibn al-'As and 'Amarah ibn al-Walid, and they gathered a gift for the Negus. We arrived, and they arrived at the Negus, and they brought him his gift, and he accepted it, and they prostrated. Then 'Amr ibn al-'As said to him: "Indeed, a people from among us have turned away from our religion, and they are in your land." The Negus said to them: "In my land?" They said: "Yes." So he sent for us. Ja'far said to us: "Let no one among you speak; I am your spokesman today." He said: We reached the Negus, and he was sitting in his assembly, with 'Amr ibn al-'As on his right and 'Amarah on his left, and the priests and monks were sitting in two rows. 'Amr ibn al-'As and 'Amarah had said to him: "They do not prostrate to you." He said: When we reached him, those who were with him from among the priests and monks rebuked us, saying: "Prostrate to the King!" Ja'far said: "We do not prostrate except to Allah." When we reached the Negus, he said: "What prevents you from prostrating?" He said: "We do not prostrate except to Allah." The Negus said to him: "And what is that?" He said: "Indeed, Allah sent among us His Messenger, and he is the Messenger whom 'Isa ibn Maryam gave glad tidings of, saying: 'A messenger who will come after me, his name is Ahmad.' He commanded us to worship Allah and not associate anything with Him, to establish prayer, and to give zakat. He commanded us to do good and forbade us from evil." He said: The Negus was pleased with his words. When 'Amr ibn al-'As saw that, he said: "May Allah rectify the King, they differ with you regarding the son of Maryam." The Negus said to Ja'far: "What does your companion say about the son of Maryam?" He said: "He says about him the word of Allah: He is the Spirit of Allah and His Word, which He cast into the virgin Mary, whom no human had touched." He said: The Negus picked up a stick from the ground and said: "O assembly of priests and monks, what these people say does not exceed what you say about the son of Maryam by the weight of this. Welcome to you and to the one from whom you have come. I bear witness that he is the Messenger of Allah, and he is the one whom 'Isa ibn Maryam gave glad tidings of. Were it not for the kingdom I am in, I would have gone to him until I carried his sandals. Stay in my land as long as you wish." He ordered food and clothing for us and said: "Return their gift to these two." He said: 'Amr ibn al-'As was a short man, and 'Amarah ibn al-Walid was a handsome man. He said: They set out on the sea to the Negus. He said: They drank. He said: And 'Amr ibn al-'As had his wife with him. When they drank wine, 'Amarah said to 'Amr: "Tell your wife to kiss me." 'Amr said to him: "Do you not feel shame?" So 'Amarah took him and threw him into the sea. 'Amr kept pleading with him until he brought him back into the ship. 'Amr harbored resentment against him for that. 'Amr said to the Negus: "Indeed, if you leave, 'Amarah will go after your family." He said: So the Negus summoned 'Amarah and blew into his private parts, and he became [living] with the wild beasts.