It was narrated that Talhah bin 'Abdullah bin 'Awf said: "I offered the funeral prayer behind Ibn 'Abbas. He recited Fatihat Al-Kitab and a Surah, which he recited loudly, such that we could hear him. When he finished I took him by the hand and asked him. He said: “(It is) Sunnah and the truth”"
SahihSahihSahih BukhariBook 21 · Hadith 170