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 (ﷺ) Muhammad.
Sahih al-Bukhari Book 23, Hadith 90
← Previous Hadith The Prophet (ﷺ) offered the funeral prayer of As-Hama An-Najash and said four Takbir.

Sahih al-Bukhari Book 23, Hadith 89 Next Hadith → I heard Ash-Shu`bi saying, "I was told by a man who had passed with the Prophet (p.b.u.h) by a grave that was separate from the other graves that he (the Prophet (ﷺ) ) led them in the prayer and they prayed behind him." I said, "O Abu `Amr! Who narrated that to you?" He replied, "Ibn `Abbas."

Sahih al-Bukhari Book 23, Hadith 91