311 – Abu Saʿīd al-Khudrī (may Allah be pleased with him) reported that the Messenger of Allah ﷺ said, “Whoever sleeps through the witr or forgets it should perform it when he wakes up or remembers.” Narrated by the Five except al-Nasāʾī. (1)

— Degree of authenticity:
This hadith is sound. It was recorded by Aḥmad, Abū Dāwūd, al-Tirmidhī, Ibn Mājah, al-Dāraqutnī (2/22), and al-Ḥākim (1/443), who remarked, “It is authentic according to the criteria of the Two Shaykhs,” and al-Dhahabī agreed.
Al-ʿIrāqī stated that the report comes by two routes:
• Through Abū Dāwūd – a sound chain.
• Through al-Tirmidhī and Ibn Mājah – a weak chain.

Points derived from the hadith
1 – The hadith shows that whoever slept through the witr until the second (true) dawn had risen, or forgot it and did not remember until daybreak, is to pray it even after the appearance of the second dawn.
2 – Since al-Ḥākim and al-Dhahabī judged the report to meet the standards of al-Bukhārī and Muslim, and Shaykh al-Albānī supported them, it stands as valid evidence for this ruling.
Nevertheless, it also falls under the general principle found in al-Bukhārī (597) and Muslim (682) on the authority of Anas, that the Prophet ﷺ said, “Whoever sleeps through a prayer or forgets it should perform it when he remembers; there is no expiation for it other than that.”