Sahih Ibn Khuzaymah 2125 — Hazrat Uthman bin Abi al-As Thaqafi

The horses of Banu Amir bin Sa’sa’ah, Hazrat Mutarrif narrates that Hazrat Uthman bin Abi al-As Thaqafi (may Allah be pleased with him) asked for milk to be brought for him to drink, so Hazrat Mutarrif said, “I am fasting.” He (Uthman) replied, “I heard the Prophet Muhammad (peace and blessings be upon him) say: ‘Fasting is a shield from the fire of Hell just like the shield of any one of you in battle.’ And I heard the Messenger of Allah (peace and blessings be upon him) say: ‘The best fasts are three days in every month.’”