It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) informed the people of the death of the Negus on the very day he died, went out with them for the prayer, arranged them in rows and said four takbirs.
This is the wording of the hadith of Imam al-Shafi'i and Abdullah; in the narration of Yahya: He went out to the prayer ground and said four takbirs. Imam al-Bukhari also narrated it in his Sahih.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6931