´Ibn Umar narrated that :` Allah's Messenger said: "When Fajr begins, then every Salat of the night and Al-Witr have gone, so perform Al-Witr before Fajr begins."
Hadith Referenceسنن ترمذي / أبواب الوتر / 469
Hadith Gradingالألبانی:صحيح، الإرواء (2 / 154) ، صحيح أبي داود (1290)
1؎: It has been mentioned in the footnote of the previous hadith that many of the noble Companions (radi Allahu anhum) and the great Imams are of the opinion that the missed witr prayer should be made up (qada), and this is the preferred view. Because if the witr is not performed, then the even-numbered units (rak‘at) of the sunnah and supererogatory (nawafil) prayers will not become odd-numbered, and Allah knows best.
Explanation & Benefits
Shaykh Dr. Abdur Rahman Freywai
1: It has been mentioned in the footnote to the previous hadith that many of the noble Companions (radi Allahu anhum) and eminent Imams (rahimahumullah) hold the view that the missed witr prayer should be made up (qada), and this is the preferred opinion. This is because if one does not perform the witr, the even-numbered units (rak‘ahs) of the Sunnah and supererogatory (nawafil) prayers will not become odd-numbered, and Allah knows best.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 469
Narrated Ibn 'Umar (RA): The Prophet (ﷺ) said: "When the dawn breaks, then the time of all night prayers including the Witr is over, so observe the Witr before dawn." [Reported by at-Tirmidhi].
The word "kull" is nominative because it is the subject (fa‘il) of "dhahaba," and "al-witr" is conjoined (ma‘tuf) to the word "kull," therefore it too will be nominative.
Source: Bulugh al-Maram: Commentary by Safiur Rahman Mubarakpuri, Page: 309