Bulugh al-Maram 2 The Book of Prayer كتاب الصلاة 275

وَعَنْ عَبْدِ اَللَّهِ بْنِ بُرَيْدَةَ , عَنْ أَبِيهِ قَالَ : قَالَ رَسُولُ اَللَّهِ – صلى الله عليه وسلم -{ اَلْوِتْرُ حَقٌّ, فَمَنْ لَمْ يُوتِرْ فَلَيْسَ مِنَّا } أَخْرَجَهُ أَبُو دَاوُدَ بِسَنَد لَيِّنٍ, وَصَحَّحَهُ اَلْحَاكِمُ . 1 . 1 – ضعيف. رواه أبو داود (1419)، والحاكم (1/305-306).

Narrated ‘Abdullah bin Buraidah (RA) from his father: Allah’s Messenger (صلى الله عليه وسلم) said: “The Witr is a duty, so he who does not offer it, is not one of us.” [Reported by Abu Dawud with a Laiyin (weak) chain of narrators and Al-Hakim graded it Sahih (authentic)].