Mutarrif, from the tribe of Banu ‘Amir bin Sa’sa’ah narrated that ‘Uthman bin Abul-‘As Ath-Thaqafi invited him to drink some milk that he poured for him. Mutarrif said:“I am fasting.” ‘Uthman said: “I heard the Messenger of Allah (ﷺ) say: ‘Fasting is a shield against the Fire just like the shield of anyone of you against fighting.’”

English translation · Sunan Ibn Majah