وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ
قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِن أحدكُم إِذا قَامَ يُصَلِّي جَاءَهُ الشَّيْطَان فَلبس عَلَيْهِ حَتَّى لايدري كَمْ صَلَّى؟ فَإِذَا وَجَدَ ذَلِكَ أَحَدُكُمْ فَلْيَسْجُدْ سجدين وَهُوَ جَالس»
The Messenger of Allah (sallallahu alayhi wa sallam) said:, “When one of you stands up to pray the devil comes to him and confuses him so that he does not know how much he has prayed. If any of you has such an experience he should perform two prostrations during the period when he sits.”* * i.e. before pronouncing the taslim.
Mishkat al-Masabih 955, Book 5, Prayer, Hadith 433. 1 min read