"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."' (Using translation from Nasāʾī 2251)
قَالَ رَسُولُ اللهِ ﷺ لَا يَصُومُ عَبْدٌ يَوْمًا فِي سَبِيلِ اللهِ إِلَّا بَاعَدَ اللهُ بِذَلِكَ الْيَوْمِ النَّارَ عَنْ وَجْهِهِ سَبْعِينَ خَرِيفًا