The Messenger of Allah ﷺ said: When any one of you is in doubt about his prayer and he does Dot know how much he has prayed, three or four (rak'ahs). he should cast aside his doubt and base his prayer on what he is sure of. then perform two prostrations before giving salutations. If he has prayed five rak'ahs, they will make his prayer an even number for him, and if he has prayed exactly four, they will be humiliation for the devil.  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا شَكَّ أَحَدُكُمْ فِي صَلاَتِهِ فَلَمْ يَدْرِ كَمْ صَلَّى ثَلاَثًا أَمْ أَرْبَعًا فَلْيَطْرَحِ الشَّكَّ وَلْيَبْنِ عَلَى مَا اسْتَيْقَنَ ثُمَّ يَسْجُدُ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ فَإِنْ كَانَ صَلَّى خَمْسًا شَفَعْنَ لَهُ صَلاَتَهُ وَإِنْ كَانَ صَلَّى إِتْمَامًا لأَرْبَعٍ كَانَتَا تَرْغِيمًا لِلشَّيْطَانِ  

The Prophet ﷺ said: When one of you is in doubt about his prayer, and does not know how much he has prayed, three or four rak'ahs, he should pray one (additional) rak'ah and make two prostrations while sitting before giving the salutation. If the (additional) rak'ah which he prayed is the fifth one, he will make it an even number by these two prostrations. If it is the fourth one, the two prostrations will be a disgrace for the devil.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا شَكَّ أَحَدُكُمْ فِي صَلاَتِهِ فَلاَ يَدْرِي كَمْ صَلَّى ثَلاَثًا أَوْ أَرْبَعًا فَلْيُصَلِّ رَكْعَةً وَيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ قَبْلَ التَّسْلِيمِ فَإِنْ كَانَتِ الرَّكْعَةُ الَّتِي صَلَّى خَامِسَةً شَفَعَهَا بِهَاتَيْنِ وَإِنْ كَانَتْ رَابِعَةً فَالسَّجْدَتَانِ تَرْغِيمٌ لِلشَّيْطَانِ  

Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar that the Messenger of Allah ﷺ said, "If you are uncertain in the prayer and do not know whether you have prayed three or four rakas, then pray a raka and make two prostrations from the sitting position before the taslim. If the raka that you prayed was the fifth, then you make it even by these two sajdas, and if it was the fourth, then the two prostrations spite Shaytan."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا شَكَّ أَحَدُكُمْ فِي صَلاَتِهِ فَلَمْ يَدْرِ كَمْ صَلَّى أَثَلاَثًا أَمْ أَرْبَعًا فَلْيُصَلِّي رَكْعَةً وَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ قَبْلَ التَّسْلِيمِ فَإِنْ كَانَتِ الرَّكْعَةُ الَّتِي صَلَّى خَامِسَةً شَفَعَهَا بِهَاتَيْنِ السَّجْدَتَيْنِ وَإِنْ كَانَتْ رَابِعَةً فَالسَّجْدَتَانِ تَرْغِيمٌ لِلشَّيْطَانِ  

[Machine] The Messenger of Allah ﷺ said: "If anyone of you has doubt in their prayer and does not know whether they prayed three or four [rak'ahs], they should disregard their doubt and proceed according to what they are certain about. Then they should perform two prostrations before concluding their Salah. Because if they prayed five [rak'ahs], it will make up for their prayer as a whole." Musa said once, "If they prayed five [rak'ahs], they would make up for their prayer. And if they completed four [rak'ahs], they would prevent Satan from harm."  

قَالَ رَسُولُ اللهِ ﷺ إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلَمْ يَدْرِ كَمْ صَلَّى ثَلَاثًا أَمْ أَرْبَعًا فَلْيَطْرَحِ الشَّكَّ وَلْيَبْنِ عَلَى مَا اسْتَيْقَنَ ثُمَّ يَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَفَإِنْ كَانَ صَلَّى خَمْسًا كَانَتْ شَفْعًا لِصَلَاتِهِ قَالَ مُوسَى مَرَّةً فَإِنْ كَانَ صَلَّى خَمْسًا شَفَعْنَ لَهُ صَلَاتَهُ وَإِنْ كَانَ صَلَّى إِتْمَامَ أَرْبَعٍ كَانَتَا تَرْغِيمًا لِلشَّيْطَانِ  

[Machine] The Prophet ﷺ said, "If anyone of you has doubts about his prayer, he should cast aside the doubt and be certain about it, and then offer two prostrations (sajdahs). If he prayed five obligatory prayers, by offering these two prostrations, they will complete them. However, if he prayed four sunnah prayers, they will be an admonition to the devil."  

قَالَ النَّبِيُّ ﷺ إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلْيُلْقِ الشَّكَّ وَلْيَبْنِ عَلَى الْيَقِينِ وَلْيُصَلِّ سَجْدَتَيْنِ فَإِنْ كَانَتْ خَمْسًا شَفَعَ بِهِمَا وَإِنْ كَانَ صَلَّى َأَرْبَعًا كَانَتَا تَرْغِيمًا لِلشَّيْطَانِ  

[Machine] The Messenger of Allah ﷺ said: "If one of you has doubts about his prayer and does not know how many units he has prayed, then he should rely on certainty until he is certain that he has completed it. Then, he should prostrate for two extra prostrations before saying the tasleem (greeting). For if his prayer was odd (witr), it will become even (shaf') by doing so, and if it was already even, then that would be a rebuke to the devil."  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلَمْ يَدْرِ كَمْ صَلَّى فَلْيَبْنِ عَلَى الْيَقِينِ حَتَّى إِذَا اسْتَيْقَنَ أَنْ قَدْ أَتَمَّ فَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ فَإِنَّهُ إِنْكَانَتْ صَلَاتُهُ وِتْرًا صَارَتْ شَفْعًا وَإِنْ كَانَتْ شَفْعًا كَانَ ذَلِكَ تَرْغِيمًا لِلشَّيْطَانِ  

“The Messenger of Allah ﷺ said: ‘If anyone of you is uncertain about his prayer, let him put aside uncertainty and act upon that which is certain. When he has made sure his prayer is complete, then let him prostrate twice. Then if his prayer was complete, that (extra) Rak’ah will be counted as voluntary, and if his prayer was lacking, that Rak’ah will complete his prayer, and the two prostrations will rub the Satan’s nose in the dust.’” (Using translation from Ibn Mājah 1210)   

قَالَ رَسُولُ اللَّهِ ﷺ «إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلْيُلْقِ الشَّكَّ وَلْيَبْنِ عَلَى الْيَقِينِ فَإِنِ اسْتَيْقَنَ التَّمَامَ سَجَدَ سَجْدَتَيْنِ فَإِنْ كَانَتْ صَلَاتُهُ تَامَّةً كَانَتِ الرَّكْعَةُ نَافِلَةً وَالسَّجْدَتَانِ وَإِنْ كَانَتْ نَاقِصَةً كَانَتِ الرَّكْعَةُ تَمَامًا لِصَلَاتِهِ وَالسَّجْدَتَانِ يُرْغِمَانِ أَنْفَ الشَّيْطَانِ»  

The Prophet ﷺ said: When one of you is in doubt about his prayer, and does not know how much he has prayed, three or four rak'ahs, he should pray one (additional) rak'ah and make two prostrations while sitting before giving the salutation. If the (additional) rak'ah which he prayed is the fifth one, he will make it an even number by these two prostrations. If it is the fourth one, the two prostrations will be a disgrace for the devil. (Using translation from Abū Dāʾūd 1026)   

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «إِذَا صَلَّى أَحَدُكُمْ فَلَمْ يَدْرِ ثَلَاثًا صَلَّى أَمْ أَرْبَعًا فَلْيُصَلِّ رَكْعَةً وَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ السَّلَامِ فَإِنْ كَانَتْ ثَالِثَةً شَفَعَتْهَا السَّجْدَتَانِ وَإِنْ كَانَتْ رَابِعَةً فَالسَّجْدَتَانِ تَرْغِيمٌ لِلشَّيْطَانِ»  

“The Messenger of Allah ﷺ said: ‘If anyone of you is uncertain about his prayer, let him put aside uncertainty and act upon that which is certain. When he has made sure his prayer is complete, then let him prostrate twice. Then if his prayer was complete, that (extra) Rak’ah will be counted as voluntary, and if his prayer was lacking, that Rak’ah will complete his prayer, and the two prostrations will rub the Satan’s nose in the dust.’” (Using translation from Ibn Mājah 1210)   

قَالَ رَسُولُ اللَّهِ ﷺ «إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلْيُلْقِ الشَّكَّ وَلْيَبْنِ عَلَى الْيَقِينِ فَإِنِ اسْتَيْقَنَ التَّمَامَ سَجَدَ سَجْدَتَيْنِ فَإِنْ كَانَتْ صَلَاتُهُ تَامَّةً كَانَتِ الرَّكْعَةُ نَافِلَةً وَالسَّجْدَتَانِ نَافِلَةً وَإِنْ كَانَتْ نَاقِصَةً كَانَتِ الرَّكْعَةُ تَمَامًا لِصَلَاتِهِ وَالسَّجْدَتَانِ تُرْغِمَانِ أَنْفَ الشَّيْطَانِ»  

The Prophet ﷺ said: When one of you is in doubt about his prayer, and does not know how much he has prayed, three or four rak'ahs, he should pray one (additional) rak'ah and make two prostrations while sitting before giving the salutation. If the (additional) rak'ah which he prayed is the fifth one, he will make it an even number by these two prostrations. If it is the fourth one, the two prostrations will be a disgrace for the devil. (Using translation from Abū Dāʾūd 1026)   

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «إِذَا صَلَّى أَحَدُكُمْ فَلَمْ يَدْرِ ثَلَاثًا صَلَّى أَمْ أَرْبَعًا فَلْيُصَلِّ رَكْعَةً وَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ السَّلَامِ فَإِنْ كَانَتْ رَابِعَةً فَالسَّجْدَتَانِ تَرْغِيمًا لِلشَّيْطَانِ وَإِنْ كَانَتْ خَامِسَةً شَفَعَتْهَا السَّجْدَتَانِ»  

The Prophet ﷺ said: When one of you is in doubt about his prayer, and does not know how much he has prayed, three or four rak'ahs, he should pray one (additional) rak'ah and make two prostrations while sitting before giving the salutation. If the (additional) rak'ah which he prayed is the fifth one, he will make it an even number by these two prostrations. If it is the fourth one, the two prostrations will be a disgrace for the devil. (Using translation from Abū Dāʾūd 1026)   

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلَمْ يَدْرِ أَصَلَّى ثَلَاثًا أَوْ أَرْبَعًا فَلْيَقُمْ فَلْيَرْكَعْ» يَعْنِي رَكْعَةً وَيَسْجُدُ سَجْدَتَيْنِ فَإِنْ كَانَتْ خَامِسَةً شَفَعَهَا بِسَجْدَتَيْنِ وَإِنْ كَانَتْ رَابِعَةٌ كَانَتِ السَّجْدَتَانِ تَرْغِيمًا لِلشَّيْطَانِ  

[Machine] The Messenger of Allah ﷺ said: "If one of you has doubt about whether he has prayed three or four units (rak'ahs), then let him pray a complete unit (rak'ah) and then make two prostrations while sitting. If that unit of prayer was the fifth, then he should make those two prostrations as a supplication. And if it was the fourth, then they serve as a deterrent to the devil." 'Uyad bin Hilal differed in his wording of the hadith.  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «إِذَا شَكَّ أَحَدُكُمْ فَلَمْ يَدْرِ أَصَلَّى ثَلَاثًا أَمْ أَرْبَعًا فَلْيُصَلِّ رَكْعَةً تَامَّةً ثُمَّ يَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ فَإِنْ كَانَتِ تِلْكَ الرَّكْعَةُ خَامِسَةً شَفَعَ بِهَاتَيْنِ السَّجْدَتَيْنِ وَإِنْ كَانَتْ رَابِعَةً كَانَتَا تَرْغِيمًا لِلشَّيْطَانِ» خَالَفَهُ عِيَاضُ بْنُ هِلَالٍ فِي لَفْظِهِ  

"إِذا صلَّى أحدُكُمْ فلم يدرِ ثلاثًا صلى أم أربعًا؟ فْلُيصلِّ ركعةً ويسجُدْ سجدتين قَبل السلام، فإنْ كانَتْ ثالثةً شفعها السَّجدتان، وإنْ كانَتْ رابعةً فالسجدتان تَرْغيمٌ للشَّيطْان".  

The Messenger of Allah ﷺ said: When any one of you is in doubt about his prayer and he does Dot know how much he has prayed, three or four (rak'ahs). he should cast aside his doubt and base his prayer on what he is sure of. then perform two prostrations before giving salutations. If he has prayed five rak'ahs, they will make his prayer an even number for him, and if he has prayed exactly four, they will be humiliation for the devil. (Using translation from Muslim 571a)   

"إذا شكَّ أحدُكُمْ في صلاتِه فلمْ يَدْرِ كم صلَّى، ثلاثًا أمْ أربْعًا؟ فليَطرحْ الشَّكَ ولْيبْنِ على ما اسْتيقَنَ ثُمَّ يَسْجُدْ سجْدَتين قْبلَ أنْ يُسلِّمَ، فإِن كانَ صلَّى خمسًا شَفعْن له صَلاته، وإنْ كانَ صلَّى إتْمامًا لأربعٍ كانتا تَرْغيما للشَّيطان".