Sa'id bin Abi Sa'id al-Maqburi narrates that he prayed the funeral prayer behind Ibn Abbas (may Allah be pleased with them both), and he recited Surah al-Fatihah aloud. Then he said: I wanted the people to know, and you too to know, that it is the Sunnah.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10777