" مَنْ صَامَ يَوْمًا فِي سَبِيلِ اللَّهِ بَاعَدَ اللَّهُ بَيْنَهُ وَبَيْنَ النَّارِ بِذَلِكَ الْيَوْمِ سَبْعِينَ خَرِيفًا "
It was narrated that Abu Saeed Al-Khudri said: "The Messenger of Allah said: 'Whoever fasts one day in the cause of Allah, Allah will separate between his face and the fire by (a distance of) seventy autumns in return for that day."'