Messenger of Allah (S) said: "Indeed the Shaitan comes to one of you in his Salat confusing him until he does now know how much he has prayed. When one of you experiences that then let him perform two prostrations while sitting." (Using translation from Tirmidhī 397)   

قَالَ رَسُولُ اللهِ ﷺ يَأْتِي أَحَدَكُمُ الشَّيْطَانُ فَيَلْبِسُ عَلَيْهِ فِي صَلَاتِهِ فَلَا يَدْرِي أَزَادَ أَمْ نَقَصَ فَإِذَا وَجَدَ أَحَدُكُمْ ذَلِكَ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ  

[Machine] The Messenger of Allah ﷺ said, "If one of you prays and forgets or does not know if they have added or missed something, they should perform two prostrations while sitting."  

قَالَ رَسُولُ اللهِ ﷺ «إِذَا صَلَّى أَحَدُكُمْ فَنَسِيَ» أَوْ قَالَ «فَلَمْ يَدْرِ زَادَ أَوْ نَقَصَ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ»  

[Machine] The Messenger of Allah ﷺ said, "If one of you makes a mistake in his prayer and does not know whether he has added or missed something, he should perform two prostrations of forgetfulness while sitting." The rest of them disagreed with him.  

قَالَ رَسُولُ اللهِ ﷺ «إِذَا سَهَا أَحَدُكُمْ فِي صَلَاتِهِ فَلَا يَدْرِي زَادَ أَوْ نَقَصَ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ» خَالَفَهُ بَقِيَّةُ  

[Machine] The Messenger of Allah ﷺ said, "If one of you prays and does not know if he has added or subtracted, he should perform two prostrations while sitting and then say the salaam."  

قَالَ رَسُولُ اللهِ ﷺ «إِذَا صَلَّى أَحَدُكُمْ فَلَا يَدْرِي أَزَادَ أَوْ نَقَصَ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ ثُمَّ يُسَلِّمُ»  

"إذَا صَلَّى أحدُكم فلمْ يدْرِ كيف صلَّى؟ فليسجدْ سجدَتين وَهُوَ جَالِسٌ".  

"إذا سَهَا أحدُكم في صلاتِه فلا يدْرى أزَادَ أمْ نقصَ؟ فليسْجدْ سجْدتين وهُوَ جَالِسٌ، ثُمَّ يُسَلِّم" .