Mentioning the Differences in the Reports from Yahya bin Abi Kathir and An-Nadr bin Shaiban
أَخْبَرَنَا 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)