" لاَ يَصُومُ عَبْدٌ يَوْمًا فِي سَبِيلِ اللَّهِ إِلاَّ بَاعَدَ اللَّهُ تَعَالَى بِذَلِكَ الْيَوْمِ النَّارَ عَنْ وَجْهِهِ سَبْعِينَ خَرِيفًا "
It was narrated that Abu Saeed Al-khudi said: "The Messenger of Allah: 'There is no worshipper who fasts a day in the cause of Allah, but Allah, the most high, will separate (a distance of) seventy autumns between his face and the fire in return for that day."'