Ibn Ishaq narrated: Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) was one of those who emigrated to the land of Abyssinia. He stayed there until the Prophet (peace and blessings be upon him) sent Sayyiduna Amr bin Umayyah (may Allah be pleased with him) to the Negus, and the Negus sent them in two ships, and they came to the Prophet (peace and blessings be upon him) after al-Hudaybiyah, around the Battle of Khaybar.
Al-Tabarani recorded it; it is munqati' (broken) in its chain, and its narrators up to Ibn Ishaq are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15937