Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
nasai:1246 – Sūwayd b. Naṣr > ʿAbdullāh > Misʿar > al-Ḥakam > Abū Wāʾil > ʿAbdullāh

"Whoever has doubt, or is not sure, let him estimate what is correct, then let him prostrate twice."  

النسائي:١٢٤٦ – أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ عَنْ مِسْعَرٍ عَنِ الْحَكَمِ عَنْ أَبِي وَائِلٍ عَنْ عَبْدِ اللَّهِ قَالَ

مَنْ شَكَّ أَوْ أَوْهَمَ فَلْيَتَحَرَّ الصَّوَابَ ثُمَّ لْيَسْجُدْ سَجْدَتَيْنِ  

See similar narrations below:

Collected by Nasāʾī, Ibn Ḥibbān, Ṭabarānī, Nasāʾī's Kubrá
nasai:1247 – Sūwayd b. Naṣr > ʿAbdullāh > Ibn ʿAwn > Ibrāhīm

"They used to say: 'If one is not sure of what he estimates is correct, then prostrate twice.'"  

النسائي:١٢٤٧ – أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ عَنِ ابْنِ عَوْنٍ عَنْ إِبْرَاهِيمَ قَالَ

كَانُوا يَقُولُونَ إِذَا أَوْهَمَ يَتَحَرَّى الصَّوَابَ ثُمَّ يَسْجُدُ سَجْدَتَيْنِ  

ذِكْرُ الْبَيَانِ بِأَنَّ الْأَمْرَ بِسَجْدَتَيِ السَّهْوِ لِلتَّحَرِّي فِي شَكِّهِ فِي الصَّلَاةِ إِنَّمَا أُمِرَ بِهَا بَعْدَ السَّلَامِ لَا قَبْلُ

ibnhibban:2659 – ʿAbdullāh b. Muḥammad al-Azdī > Isḥāq b. Ibrāhīm > ʿUbayd b. Saʿīd al-Umawī > Sufyān > Manṣūr > Ibrāhīm > ʿAlqamah > ʿAbdullāh

[Machine] From the Messenger of Allah ﷺ , he said: "If any of you is doubtful about his prayer, let him correct it, then let him offer the salutation, and then let him prostrate twice."  

ابن حبّان:٢٦٥٩ – أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ الْأَزْدِيُّ قَالَ حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ قَالَ أَخْبَرَنَا عُبَيْدُ بْنُ سَعِيدٍ الْأُمَوِيُّ قَالَ حَدَّثَنَا سُفْيَانُ عَنْ مَنْصُورٍ عَنْ إِبْرَاهِيمَ عَنْ عَلْقَمَةَ عَنْ عَبْدِ اللَّهِ

عَنْ رَسُولِ اللَّهِ ﷺ قَالَ «إِذَا شَكَّ أَحَدُكُمْ فِي صَلَاتِهِ فَلْيَتَحَرَّ الصَّوَابَ ثُمَّ لْيُسَلِّمْ ثُمَّ لْيَسْجُدْ سَجْدَتَيْنِ»  

tabarani:9183 – ʿAlī b. ʿAbd al-ʿAzīz > Abū Nuʿaym > Misʿar > al-Ḥakam > Abū Wāʾil

"Whoever us not sure about his prayer, then let him estimate what is correct, then let him prostrate twice after he finished his prayer, while he is sitting." (Using translation from Nasāʾī 1245)   

الطبراني:٩١٨٣ – حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ الْعَزِيزِ ثنا أَبُو نُعَيْمٍ ثنا مِسْعَرٌ عَنِ الْحَكَمِ عَنْ أَبِي وَائِلٍ قَالَ قَالَ

عَبْدُ اللهِ «مَنْ شَكَّ أَوْ وَهِمَ فِي صَلَاتِهِ فَلْيَتَحَرَّ ثُمَّ يَسْجُدْ سَجْدَتَيْنِ»  

nasai-kubra:1170 – Sūwayd b. Naṣr > ʿAbdullāh > Misʿar > al-Ḥakam > Abū Wāʾil > ʿAbdullāh

"Whoever has doubt, or is not sure, let him estimate what is correct, then let him prostrate twice." (Using translation from Nasāʾī 1246)  

الكبرى للنسائي:١١٧٠ – أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ قَالَ أَخْبَرَنَا عَبْدُ اللهِ عَنْ مِسْعَرٍ عَنِ الْحَكَمِ عَنْ أَبِي وَائِلٍ عَنْ عَبْدِ اللهِ قَالَ

«مَنْ شَكَّ أَوْ أَوْهَمَ فَلْيَتَحَرَّ ثُمَّ لِيَسْجُدَ سَجْدَتَيْنِ»  

nasai-kubra:1171 – Sūwayd > ʿAbdullāh > Ibn ʿAwn > Ibrāhīm

"They used to say: 'If one is not sure of what he estimates is correct, then prostrate twice.'" (Using translation from Nasāʾī 1247)  

الكبرى للنسائي:١١٧١ – أَخْبَرَنَا سُوَيْدُ قَالَ أَخْبَرَنَا عَبْدُ اللهِ عَنِ ابْنِ عَوْنٍ عَنْ إِبْرَاهِيمَ قَالَ

كَانُوا يَقُولُونَ «إِذَا أَوْهَمَ يَتَحَرَّى الصَّوَابَ ثُمَّ يَسْجُدَ سَجْدَتَيْنِ»