It was narrated from Abu Hurairah that the Prophet (ﷺ) said:“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.”
حَدَّثَنَا سُفْيَانُ بْنُ وَكِيعٍ، حَدَّثَنَا يُونُسُ بْنُ بُكَيْرٍ، حَدَّثَنَا ابْنُ إِسْحَاقَ، حَدَّثَنِي الزُّهْرِيُّ، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ 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 " .
IbnMaja
Establishing the Prayer and the Sunnah Regarding Them • Hadith 1216