Language:
كتاب الجنائز
23  
Funerals (Al-Janaa'iz)
(4)
Chapter: A man who informs the relatives of the deceased person (of his death) by himself
(4)
باب الرَّجُلِ يَنْعَى إِلَى أَهْلِ الْمَيِّتِ بِنَفْسِهِ
Sahih al-Bukhari 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).

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَعَى النَّجَاشِيَّ فِي الْيَوْمِ الَّذِي مَاتَ فِيهِ، خَرَجَ إِلَى الْمُصَلَّى، فَصَفَّ بِهِمْ وَكَبَّرَ أَرْبَعًا‏.‏
Reference : Sahih al-Bukhari 1245
In-book reference : Book 23, Hadith 8
USC-MSA web (English) reference : Vol. 2, Book 23, Hadith 337
  (deprecated numbering scheme)