The Prophet ﷺ said, "A righteous man from Abyssinia has died today. Come and form rows."So we formed rows, and the Prophet ﷺ performed the funeral prayer over him while we were behind him.
حدثنا عبد الرزاق أخبرنا ابن جريج أخبرني عطاء أنه سمع
قال النبي ﷺ قد توفي اليوم رجل صالح من الحبش هلم فصفوا قال فصففنا فصلى النبي ﷺ عليه ونحن
Its chain of transmission is sahih. It is found in Bukhari 2/109, in the book of funerals, chapter on rows for the funeral prayer, and in Tirmidhi 3/357, no. 1039, in the book of funerals, chapter on what has been mentioned regarding the Prophet's ﷺ prayer over Najashi. Tirmidhi said, hasan sahih gharib.