Fast one day for Allah's sake; strive towards righteousness; seek protection through faithfulness; earn rewards through piety; do good deeds.

This hadith is about the reward for fasting in the cause of Allah. It was narrated by An-Numan bin Abi 'Ayyash and Abu Saeed Al-Khudri that Prophet Muhammad said that whoever fasts one day in the cause of Allah will be protected from Hellfire by a distance equal to seventy autumns. This means that if someone fasts, they will be rewarded with protection from punishment on Judgment Day, which is an immense reward indeed! The hadith also teaches us to always strive to do good deeds as they can bring us closer to God and save us from His wrath.