The Messenger of Allah ﷺ said, "Whoever fasts a single day in the path of Allah , Allah will distance Hellfire from him by a journey of a hundred years."
أخبرنا محمود بن خالد عن محمد بن شعيب قال أخبرني يحيى بن الحارث عن القاسم أبي عبد الرحمن أنه حدثه
عن رسول الله ﷺ قال من صام يوما في سبيل الله عز وجل باعد الله منه جهنم مسيرة مائة عام
Sourcing. [Its isnad is hasan] Tabarani narrated it in Al-Kabir, 335/17, no. 927, from the hadith of Muhammad bin Shuayb, through the same chain, and it is also in Kubra, no. 2562. The hadith has corroborating witnesses.Qasim Abu Abdul-Rahman's hearing from Uqbah is established, as noted in Sunan al-Kubra of Nasai, no. 10725.