(36) باب فَضْلِ الصَّوْمِ فِي سَبِيلِ اللَّهِ
Narrated Abu Sa`id:
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."
Reference: Sahih al-Bukhari 2840
In-book reference: Book 56, Hadith 56
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 52, Hadith 93