The Messenger of Allah ﷺ said, "Whoever fasts a single day for the sake of Allah, Allah will distance the Fire from his face by seventy autumns because of that day."
حدثنا ابن نمير أخبرنا سفيان بن سعيد بن مسروق عن سمي عن النعمان بن أبي عياش
قال رسول الله ﷺ من صام يوما في سبيل الله باعد الله بذلك اليوم النار عن وجهه سبعين خريفا
Its isnad is sahih. Ibn Numayr is Abdullah, and Sufyan is Thawri the imam, and Sumayy is the freed slave of Abu Bakr bin Abdul-Rahman, who is trustworthy, and Numan bin Abu Ayyash Zurqi is trustworthy, and his father was a companion. The hadith has already appeared at 11344.