Sunan an-Nasa'i 1988
سنن النسائي#1988SahihIt was narrated that Talhah bin 'Abdullah said:"I offered the funeral prayer behind Ibn 'Abbas and I heard him reciting Fatihat Al-Kitab. When he finished I took him by the hand and asked him. 'Did you recite?' He said: 'Yes, it is the truth and the Sunnah
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Bukhari
In-book reference: 21:171