One who fasts a single day is distanced from Hellfires at a distance of seventy years
BUKHARI 2840:
from Abū Saʿīd —
I heard the Prophet ﷺ saying, "Indeed, anyone who fasts for one day for Allah's Pleasure, Allah will keep his face away from the (Hell) fire for (a distance covered by a journey of) seventy years."
البخاري ٢٨٤٠:
عن ابو سعيد —
سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ: «مَنْ صَامَ يَوْمًا فِي سَبِيلِ اللَّهِ بَعَّدَ اللَّهُ وَجْهَهُ عَنِ النَّارِ سَبْعِينَ خَرِيفًا».