Sunan an-Nasa'i 2209
سنن النسائي#2209Da'ifأَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا النَّضْرُ بْنُ شُمَيْلٍ، قَالَ أَنْبَأَنَا الْقَاسِمُ بْنُ الْفَضْلِ، قَالَ حَدَّثَنَا النَّضْرُ بْنُ شَيْبَانَ، عَنْ أَبِي سَلَمَةَ، فَذَكَرَ مِثْلَهُ وَقَالَ " مَنْ صَامَهُ وَقَامَهُ إِيمَانًا وَاحْتِسَابًا " .
A similar report was narrated from Abu Salamah and he said:"Whoever fasts it and spends its nights in prayer out of faith and in the hope of reward." (Daif)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahDaif
Al-AlbaniDaif
Zubair Ali ZaiDaif
In-book reference: 22:120