From 'Urwah [bin Az-Zubair], and Sulaiman bin Yasar, that they reported to him from Abu Hurairah that the Prophet ﷺ said: "Whoever fasts a day in the cause of Allah, Allah shall distance him from the Fire by seventy autumns." One of them said "seventy" and the other said: "forty".

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ صَامَ يَوْمًا فِي سَبِيلِ اللَّهِ زَحْزَحَهُ اللَّهُ عَنِ النَّارِ سَبْعِينَ خَرِيفًا أَحَدُهُمَا يَقُولُ سَبْعِينَ وَالآخَرُ يَقُولُ أَرْبَعِينَ