Eating right at the start of Fajr time

Answer

The hadith is as follows: *إِذَا سَمِعَ أَحَدُكُمُ النِّدَاءَ، وَالإِنَاءُ عَلَى يَدِهِ، فَلَا يَضَعْهُ حَتَّى يَقْضِيَ حَاجَتَهُ مِنْهُ* — Abu Hurayrah reported that the Messenger of Allah ﷺ said: "If one of you hears the call (to prayer) while the vessel is in his hand, then he should not put it down until he fulfills his need from it." (Abu Dawud). This hadith is considered by some scholars as weak. Others interpreted it to mean if there is doubt about whether Fajr has truly entered, while others say it refers to the first adhan which used to be given before true Fajr, not the actual time of Fajr. Therefore, the relied-upon position is: once you are sure Fajr has entered, you must stop immediately. Continuing to eat knowingly after that would invalidate the fast.