Abu Mijlaz narrated that Ibn ‘Umar said:“The Messenger of Allah (ﷺ) said: ‘Night prayers are to be offered two by two, and Witr is one Rak’ah.’ I said: ‘What do you think if I become drowsy and I want to sleep?’ He said: ‘Put “what do you think” up there with that star? (i.e., don’t think about it at all).’ I raised my head and saw As- Simak.* He repeated that the Messenger of Allah (ﷺ) said, ‘Night prayers are to be offered two by two, and Witr is one Rak’ah, before dawn.’”* Here, As-Simak refers to a star or stars, either Arcturus (As-Simak Ar-Ramih) or Spica, also called Alpha Virginis (As-Simak Al-A'zal).
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ الْمَلِكِ بْنِ أَبِي الشَّوَارِبِ، حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا عَاصِمٌ، عَنْ أَبِي مِجْلَزٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى وَالْوِتْرُ رَكْعَةٌ " قُلْتُ أَرَأَيْتَ إِنْ غَلَبَتْنِي عَيْنِي أَرَأَيْتَ إِنْ نِمْتُ قَالَ اجْعَلْ أَرَأَيْتَ عِنْدَ ذَلِكَ النَّجْمِ . فَرَفَعْتُ رَأْسِي فَإِذَا السِّمَاكُ ثُمَّ أَعَادَ فَقَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى. وَالْوِتْرُ رَكْعَةٌ قَبْلَ الصُّبْحِ " .
IbnMaja
Establishing the Prayer and the Sunnah Regarding Them • Hadith 1175