أَخْبَرَنَا مُحَمَّدُ بْنُ هَاشِمٍ، أَنْبَأَنَا الْوَلِيدُ، أَنْبَأَنَا ابْنُ جُرَيْجٍ، عَنْ عَبْدِ اللَّهِ بْنِ مُسَافِعٍ، عَنْ عُتْبَةَ بْنِ مُحَمَّدِ بْنِ الْحَارِثِ، عَنْ عَبْدِ اللَّهِ بْنِ جَعْفَرٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ شَكَّ فِي صَلاَتِهِ فَلْيَسْجُدْ سَجْدَتَيْنِ بَعْدَ التَّسْلِيمِ " .
It was narrated 'Abdullah bin Ja'far that : The Messenger of Allah (PBUH) said: "Whoever has doubt during his prayer, let him prostrate twice after he said the taslim." Translation Not Available
Book Ref: Sunan An Nisai Book 13 Hadith 1249
Web Ref: Sunan An Nisai Vol 2 Book 13 Hadith 1250