310 – Abu Saʿīd al-Khudrī (may Allah be pleased with him) reported that the Prophet ﷺ said, “Observe the witr before dawn breaks.” Narrated by Muslim.
Ibn Ḥibbān also recorded: “Whoever reaches daybreak without having prayed the witr has no witr.” (1)

Degree of authenticity:
Ibn Ḥibbān’s version has a sound chain. Ibn Khuzaymah and al-Ḥākim (1/443) likewise declared it authentic, and al-Dhahabī concurred. Al-Ḥākim produced a supporting narration from Ibn ʿUmar, graded it authentic, and al-Dhahabī agreed with him.

Points derived from the hadith
1 – The witr belongs to the night prayer, yet it is placed at the end to leave the total number of rakʿahs odd, just as the daytime prayers are concluded with the sunset prayer, which likewise makes their total odd.

2 – The last time for witr is the appearance of the second (true) dawn. Once dawn has risen, its time has lapsed, and whoever performs it after daybreak has no witr. Ibn al-Mundhir said: There is unanimous agreement that the period between the nightfall (ʿIshāʾ) prayer and dawn is the time allotted for witr. Its beginning, as noted above, is after the nightfall prayer, even if that prayer was offered early in combination with Maghrib.

3 – Ibn al-Mundhir also transmitted from a number of the early scholars that the witr has two windows: an optional time that ends with the second dawn, and an exceptional time—allowed for those with an excuse—that extends until the dawn (Fajr) prayer is performed.

4 – The apparent purport of the hadith is that whoever lets the time for witr expire through deliberate neglect forfeits its reward. The ruling for one who slept through it or forgot it will be discussed in the next hadith, Allah willing.