Sahih Bukhari Volume 002, Book 023, Hadith Number 412.

Narated By Abu Huraira : Allah's Apostle informed about the news of the death of An-Najash (King of Ethiopia) on the day he expired. He said, "Ask Allah's forgiveness for your brother. " Narrated Abu Huraira: The Prophet made them align in rows at the Musalla and said four Takbir.