That the Prophet ﷺ said: "A worshipper does not fast a day in the cause of Allah except that, that day (of fasting) distances the Fire from his face by seventy autumns."
قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَصُومُ عَبْدٌ يَوْمًا فِي سَبِيلِ اللَّهِ إِلاَّ بَاعَدَ ذَلِكَ الْيَوْمُ النَّارَ عَنْ وَجْهِهِ سَبْعِينَ خَرِيفًا