Funerals (Al-Janaa'iz)
Bukhari :: Book 2 :: Volume 23 :: Hadith 398
Narrated Jabir bin 'Abdullah :
A funeral procession passed in front of us and the Prophet stood up and we too stood up. We said, 'O Allah's Apostle! This is the funeral procession of a Jew." He said, "Whenever you see a funeral procession, you should stand up."