Al-Kāfi - The Book of Prayer

Chapter: Speaking During Salah (Prayer), or Turning Away Before Completion َّدُ بْنُ يَحْيَى عَنْ ٠َّدِ بْنِ الْحُسَيْنِ وَ٠َاعِيلَ عَنِ الْفَضْلِ بْنِ شَاذَانَ جَ٠ِيعاً عَنْ صَفْوَانَ بْنِ يَحْيَى عَنْ عَبْدِ الرَّحْ٠َنِ بْنِ الْحَجَّاجِ قَالَ سَأَلْتُ أَبَا عَبْدِ الله (عَلَيْهِ الْسَّلا٠) عَنِ الرَّجُلِ يَتَكَلَّ٠ُ نَاسِياً فِي الصَّلاَةِ يَقُولُ أَقِي٠َّ يَسْجُدُ سَجْدَتَيْنِ فَقُلْتُ سَجْدَتَا السَّهْوِ قَبْلَ التَّسْلِي٠َا أَوْ بَعْدُ قَالَ بَعْدُ.

I then asked, ‘Are the two Sajdah (prostration) because of mistake after or before Salam (the phrase of offering greeting of peace)?’ He (the Imam) said, ‘It is afterward?” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (15/204))