Sahih Al Bukhari Hadith Number 1335

Narrated Talha bin `Abdullah bin `Auf: I offered the funeral prayer behind Ibn `Abbas and he recited Al-Fatiha and said, “You should know that it (i.e. recitation of Al-Fatiha) is the tradition of the Prophet (peace be upon him) Muhammad.

23  Funerals (Al-Janaa’iz)
Hadith number 1335
Volume no 2
Chapter: 65 (The recitation of Surah Al-Fathiha in the funeral Salat)