Muhammad bin 'Abdur Rahman محمد بن عبد الرحمن بن نوفل · The Book of Fasting

"Whoever fasts a day in the cause of Allah, Allah will separate his face from the heat of Hell (a distance of) seventy autumns."

"The Messenger of Allah said: Whoever fasts a day in the cause of Allah, Allah will separate his face (a distance of) seventy autumns from the fire in return for that day."

"Whoever fasts one day in the cause of Allah, the mighty and sublime, Allah will separate him the distance of one hundred years from the fire."

"The Messenger of Allah said: 'It is not righteousness to fast when traveling."' (Sahih) Abu 'Abdur-Rahman (An-Nasai) said: This is a mistake, and what is correct is the one that is before it. We do not know of anyone who followed up Ibn Kathir.

the Messenger of Allah saw some people gathered around a man, so he asked (what was happening) and they said: "It is a man who is exhausted because of fasting." The Messenger of Allah said: "It is not righteousness to fast when traveling."

"O Messenger of Allah, I feel able to fast while traveling." He said: "If you wish then fast and if you wish then do not fast."