The Book of Fasting
22/44. Chapter:
The Reward of one who fasts one day in the cause of Allah, The Mighty And Sublime, And Mentioning The Differences Reported From Suhail Bin Abi Salih In The Narration About That
Sunan an-Nasai
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عَبْدِ الْحَكَمِ، عَنْ شُعَيْبٍ، قَالَ أَنْبَأَنَا اللَّيْثُ، عَنِ ابْنِ الْهَادِ، عَنْ سُهَيْلٍ، عَنِ ابْنِ أَبِي عَيَّاشٍ، عَنْ أَبِي سَعِيدٍ، أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَا مِنْ عَبْدٍ يَصُومُ يَوْمًا فِي سَبِيلِ اللَّهِ عَزَّ وَجَلَّ إِلاَّ بَعَّدَ اللَّهُ عَزَّ وَجَلَّ بِذَلِكَ الْيَوْمِ وَجْهَهُ عَنِ النَّارِ سَبْعِينَ خَرِيفًا " .
It was narrated from Abu Saeed that he heard the Messenger of Allah say: "There is no worshipper who fasts a day in the cause of Allah, the mighty and sublime, but Allah the mighty and sublime, will separate his face from the fire by (a distance of) seventy autumns in return for that day."
Reference : Sunan an-Nasa'i 2248In-book reference : Book 22, Hadith 159English translation : Vol. 3, Book 22, Hadith 2250