Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions. Wa alaikum assalam wa rahmatullahi wa barakatuh. As to what follows: In response to your question, we say: This hadith was transmitted by Ahmad and Abu Dawud from the hadiths of ‘Abdullah ibn Buraidah. He said, “The Messenger of Allah said, “The witr is a duty, so he who does not observe it does not belong to us” [Abu Dawud (1419)]. The hadith is a narration of ‘Ubaydullah ibn ‘Abdullah al-‘Ataki from ‘Abdullah ibn Buraidah from his father. The hadith was graded as authentic by al-Hakim in his book al-Mustadrak. It was graded as weak by ibn al-Jawzi. In al-‘Ilal al-Mutaanahiyyah (1/447), he said, “This hadith is not authentic”. Al-Bukhari said, “Al-‘Ataki narrates denounced hadiths”. Ibn Hibban said, “He narrates inverted hadiths which are not narrated by the authentic narrators.” In Talkhis al-Habeer (2/20), ibn Hajar said, “In the chain of narrators of the hadith there is ‘Ubaydullah ibn ‘Abdullah al-‘Ataki al-Ghurama Abu Ayyub. He was graded as a weak narrator by al-Bukhari and an-Nasai.” In Bulugh al-Maram, ibn Hajar said, “The hadith was transmitted by Abu Dawud with a weak chain of narrators. It is supported by a weak hadith from Abu Hurairah (may Allah be pleased with him) which was transmitted by Ahmad. Thus the hadith in question is not authentic. And Allah knows best.