Al-Kāfi - The Book of Prayer

Chapter: Qunut (Supplication after Recitation in Second Rak‘at) in Friday Salah (Prayer) 3ـ عَلِيُّ بْنُ إِبْرَاهِي٠َّدِ بْنِ عِيسَى عَنْ يُونُسَ عَنْ أَبَانٍ عَنْ إِسْ٠َاعِيلَ الْجُعْفِيِّ عَنْ عُ٠َرَ بْنِ حَنْظَلَةَ قَالَ قُلْتُ لأَبِي عَبْدِ الله (عَلَيْهِ الْسَّلا٠) الْقُنُوتُ يَوْ٠ُعَةِ فَقَالَ أَنْتَ رَسُولِي إِلَيْهِ٠ْ فِي هَذَا إِذَا صَلَّيْتُ٠َاعَةٍ فَفِي الرَّكْعَةِ الأولَى وَإِذَا صَلَّيْتُ٠ْ وُحْدَاناً فَفِي الرَّكْعَةِ الثَّانِيَةِ قَبْلَ الرُّكُوعِ.

When performing in congregation, it is in the first Rak‘at, but when performing alone, it is in the second Rak‘at before Ruku‘ (bowing down on one’s knees).”’ وثق - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (15/366))