The Prophet Muhammad informed his companions about the death of the King of Ethiopia on the day he died and told them to ask Allah for forgiveness for their brother. The Prophet led the companions in praying at the Musalla, where he performed the Takbir ritual four times.

1. ASK ALLAH'S FORGIVENESS FOR YOUR BROTHER

2. Narrated 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.
(Sahih Al-Bukhari, Volum # 2, Book 23, Hadith # 412)