When you offer the prayer, and you are in doubt about the number of rak'ahs whether offered three or four, and you have prayed four rak'ahs in all probability in your opinion, you should recite tashahhud and make two prostrations while you are sitting before giving the salutation. afterwards you should recite the tashahhud and give the salutation again. Abu Dawud said: This tradition has been narrated by 'Abd al-Wahid from Khusaif, but he did not report it as a statement of the Prophet ﷺ. The version of 'Abd al-Wahid has been corroborated by Sufyan, Sharik, and Isra'il. They differed amongst themselves about the text of the tradition and they did not narrate it with the continuous chain up to the Prophet ﷺ.  

عَنْ رَسُولِ اللَّهِ ﷺ قَالَ إِذَا كُنْتَ فِي صَلاَةٍ فَشَكَكْتَ فِي ثَلاَثٍ أَوْ أَرْبَعٍ وَأَكْبَرُ ظَنِّكَ عَلَى أَرْبَعٍ تَشَهَّدْتَ ثُمَّ سَجَدْتَ سَجْدَتَيْنِ وَأَنْتَ جَالِسٌ قَبْلَ أَنْ تُسَلِّمَ ثُمَّ تَشَهَّدْتَ أَيْضًا ثُمَّ تُسَلِّمُ  

When you offer the prayer, and you are in doubt about the number of rak'ahs whether offered three or four, and you have prayed four rak'ahs in all probability in your opinion, you should recite tashahhud and make two prostrations while you are sitting before giving the salutation. afterwards you should recite the tashahhud and give the salutation again. Abu Dawud said: This tradition has been narrated by 'Abd al-Wahid from Khusaif, but he did not report it as a statement of the Prophet ﷺ. The version of 'Abd al-Wahid has been corroborated by Sufyan, Sharik, and Isra'il. They differed amongst themselves about the text of the tradition and they did not narrate it with the continuous chain up to the Prophet ﷺ. (Using translation from Abū Dāʾūd 1028)   

عَنِ النَّبِيِّ ﷺ قَالَ «إِذَا كُنْتَ فِي صَلَاةِ فَشَكَكْتَ فِي ثَلَاثٍ وَأَرْبَعٍ وَأَكْثَرُ ظَنِّكَ عَلَى أَرْبَعٍ تَشَهَّدْتَ ثُمَّ سَجَدْتَ قَبْلَ أَنْ تُسَلِّمَ ثُمَّ تَشَهَّدْتَ أَيْضًا ثُمَّ سَلِّمْ»  

When you offer the prayer, and you are in doubt about the number of rak'ahs whether offered three or four, and you have prayed four rak'ahs in all probability in your opinion, you should recite tashahhud and make two prostrations while you are sitting before giving the salutation. afterwards you should recite the tashahhud and give the salutation again. Abu Dawud said: This tradition has been narrated by 'Abd al-Wahid from Khusaif, but he did not report it as a statement of the Prophet ﷺ. The version of 'Abd al-Wahid has been corroborated by Sufyan, Sharik, and Isra'il. They differed amongst themselves about the text of the tradition and they did not narrate it with the continuous chain up to the Prophet ﷺ. (Using translation from Abū Dāʾūd 1028)   

أَنَّ رَسُولَ اللهِ ﷺ قَالَ إِذَا كُنْتَ فِي الصَّلَاةِ فَشَكَكْتَ فِي ثَلَاثٍ أَوْ أَرْبَعٍ وَأَكْثَرَ أَظُنُّكَ عَلَى أَرْبَعٍ تَشَهَّدْتَ ثُمَّ سَجَدْتَ سَجْدَتَيْنِ وَأَنْتَ جَالِسٌ قَبْلَ أَنْ تُسَلِّمَ ثُمَّ تَشَهَّدْتَ أَيْضًا ثُمَّ سَلَّمْتَ وَهَذَا غَيْرُ قَوِيٍّ وَمُخْتَلَفٌ فِي رَفَعِهِ وَمَتْنِهِ  

[Machine] The translator of this passage is uncertain about the exact meaning and is unable to provide an English translation.  

عَنْ رَسُولِ اللهِ ﷺ إِذَا كُنْتَ فِي صَلَاةٍ فَشَكَكْتَ فِي ثَلَاثٍ أَوْ أَرْبَعٍ وَأَكْثَرُ ظَنِّكَ عَلَى أَرْبَعٍ تَشَهَّدْتَ ثُمَّ سَجَدْتَ سَجْدَتَيْنِ وَأَنْتَ جَالِسٌ قَبْلَ أَنْ تُسَلِّمَ ثُمَّ تَشَهَّدْتَ أَيْضًا ثُمَّ تُسَلِّمَ قَالَ أَبُو دَاوُدَ وَكَذَا  

When you offer the prayer, and you are in doubt about the number of rak'ahs whether offered three or four, and you have prayed four rak'ahs in all probability in your opinion, you should recite tashahhud and make two prostrations while you are sitting before giving the salutation. afterwards you should recite the tashahhud and give the salutation again. Abu Dawud said: This tradition has been narrated by 'Abd al-Wahid from Khusaif, but he did not report it as a statement of the Prophet ﷺ. The version of 'Abd al-Wahid has been corroborated by Sufyan, Sharik, and Isra'il. They differed amongst themselves about the text of the tradition and they did not narrate it with the continuous chain up to the Prophet ﷺ. (Using translation from Abū Dāʾūd 1028)   

"إذَا كُنْتَ في صَلاةٍ، وشَككْتَ في ثلاث وأرْبَعٍ، وأكثرُ ظَنِّكَ على أرْبَعٍ، تشهَّدتَ ثُمَّ سجدْتَ سجْدتينِ وأنْتَ جَالِسٌ قبْلَ أنْ تُسَلِّمَ، ثُمَّ تَشهَّدْتَ أيضًا، ثُمَّ تُسَلِّمُ".