The Supplication of Qunoot in Witr Prayer
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 72
وَ رَوَى عُمَرُ بْنُ يَزِيدَ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: «مَنْ قَالَ فِي وَتْرِهِ إِذَا أَوْتَرَ: أَسْتَغْفِرُ اَللَّهَ رَبِّي وَ أَتُوبُ إِلَيْهِ سَبْعِينَ مَرَّةً وَ وَاظَبَ عَلَى ذَلِكَ حَتَّى تَمْضِيَ سَنَةٌ كَتَبَهُ اَللَّهُ عِنْدَهُ مِنَ «اَلْمُسْتَغْفِرِينَ بِالْأَسْحٰارِ » وَ وَجَبَتْ لَهُ اَلْجَنَّةُ وَ اَلْمَغْفِرَةُ مِنَ اَللَّهِ عَزَّ وَ جَلَّ.
It is narrated from Umar ibn Yazid that Imam Jafar ibn Muhammad Al-Sadiq عليه السلام that He said: "Whoever says during his Witr prayer (while performing the single-unit prayer of Witr) 'Astaghfirullah Rabbi wa Atubu Ilayh' (I seek forgiveness from Allah سبحانه وتعالى, my Lord عز وجل, and I turn to Him in repentance) seventy times, and continues to do so regularly until a year passes, Allah سبحانه وتعالى will write him among 'those who seek forgiveness in the early hours of the morning,' and Paradise and forgiveness from Allah سبحانه وتعالى, the Mighty and Glorious, will become obligatory for him."
- Ṣaḥīḥ al-Faqīh