Sunan an-Nasa'i 2109
سنن النسائي#2109Da'ifIt was narrated from abu Bakrah that the Prophet said; 'None of you should say:'I fasted Ramadan' or 'I prayed Qiyam throughout the whole month."' I do not know whether he dislike self-praise or he said: "Inevitably there will be heedlessness and sleep." (Da 'if)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahDaif
Al-AlbaniDaif
Zubair Ali ZaiDaif
In-book reference: 22:20