From Sahih Bukhari (Hadith 1245):
Narrated Abu Huraira:Allah's Messenger (ﷺ) informed (the people) about the death of An-Najashi on the very day he died. He went towards the Musalla (praying place) and the people stood behind him in rows. He said four Takbirs (i.e. offered the Funeral prayer)
Reference: Bukhari 1245