Is it obligatory to make up a fast if one ate while doubting the breaking of dawn (Fajr)?
General Chapter
Al-Mughni
Book of Fasting
Primary text
If a person eats while doubting whether dawn has broken, and the matter remains unclear, there is no obligation to make up that day's fast. Such a person is permitted to continue eating until certainty regarding the breaking of dawn is established. This view is held by Ahmad, Ibn Abbas, At'a, Al-Awza'i, Al-Shafi'i, and the Ashab al-Ra'i (Hanafi jurists). A similar meaning is narrated from Abu Bakr Al-Siddiq and Ibn Umar (may Allah be pleased with them). The evidence for this is the saying of Allah Almighty: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread." (Quran 2:187), which mandates stopping the eating only upon certainty of dawn. Furthermore, the Prophet (peace be upon him) said: "Eat and drink until Ibn Umm Maktum calls the Adhan," and he was a blind man who would not give the call until he was told, "It has become morning."
Supporting text
Imam Malik ruled that making up the fast is obligatory because the default state is that the obligation of the fast remains due on the person's account, and doubt does not remove it. He reasoned that since the person ate while doubting during the daytime or nighttime period, the fast becomes due, just as if one ate while doubting the setting of the sun.