“The Satan comes to any one of you while he is praying and comes between him and his soul, until he does not know whether he as added something or omitted something. If that happens, then he should prostrate twice before the Salam, then he should say the Salam.”  

أَنَّ النَّبِيَّ ﷺ قَالَ إِنَّ الشَّيْطَانَ يَأْتِي أَحَدَكُمْ فِي صَلاَتِهِ فَيَدْخُلُ بَيْنَهُ وَبَيْنَ نَفْسِهِ حَتَّى لاَ يَدْرِي زَادَ أَوْ نَقَصَ فَإِذَا كَانَ ذَلِكَ فَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ ثُمَّ يُسَلِّمْ  

“The Satan comes between the son of Adam and his soul, and he does not know how many Rak’ah he has prayed. If a person notices that, then let him prostrate twice before he says the Salam.”  

أَنَّ النَّبِيَّ ﷺ قَالَ إِنَّ الشَّيْطَانَ يَدْخُلُ بَيْنَ ابْنِ آدَمَ وَبَيْنَ نَفْسِهِ فَلاَ يَدْرِي كَمْ صَلَّى فَإِذَا وَجَدَ ذَلِكَ فَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ