One who fasts a single day is distanced from Hellfires at a distance of seventy years
MUSLIM 1153a:
from Abū Saʿīd al-Khudrī —
Every servant of Allah who observes fast for a day in the way of Allah, Allah would remove, because of this day, his face farther from the Fire (of Hell) to the extent of seventy years' distance.
مسلم ١١٥٣a:
عن ابو سعيد الخدري —
قَالَ رَسُولُ اللَّهِ ﷺ: «مَا مِنْ عَبْدٍ يَصُومُ يَوْمًا فِي سَبِيلِ اللَّهِ إِلاَّ بَاعَدَ اللَّهُ بِذَلِكَ الْيَوْمِ وَجْهَهُ عَنِ النَّارِ سَبْعِينَ خَرِيفًا۔»