‘Ata b. Yasar said that Abu Sa'id reported God’s Messenger as saying, “When one of you is in doubt aoout his prayer and does not know how much he has prayed, three or four <i>rak'as</i>, he should subtract what he is doubtful about and base his prayer on what he is sure of, then perform two prostrations before giving the salutation. If he has prayed five <i>rak'as</i> they will make his prayer an even number for him, and if he has prayed exactly four they will be a humbling for the devil.” Muslim transmitted it, and Malik transmitted it from ‘Ata’ in <i>mursal</i> form. In his version it says, “he will make it an even number by these two prostrations.”

وَعَن عَطاء بن يسَار وَعَنْ أَبِي سَعِيدٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلَمْ يَدْرِ كَمْ صَلَّى ثَلَاثًا أم أَرْبعا فليطرح الشَّك وليبن عَلَى مَا اسْتَيْقَنَ ثُمَّ يَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ فَإِنْ كَانَ صَلَّى خَمْسًا شَفَعْنَ لَهُ صَلَاتَهُ وَإِنْ كَانَ صَلَّى إِتْمَامًا لِأَرْبَعٍ كَانَتَا تَرْغِيمًا لِلشَّيْطَانِ» . رَوَاهُ مُسْلِمٌ وَرَوَاهُ مَالِكٌ عَنْ عَطَاءٍ مُرْسَلًا. وَفِي رِوَايَتِهِ: «شَفَعَهَا بِهَاتَيْنِ السَّجْدَتَيْنِ»