The Messenger of Allah ﷺ said: "Whoever has doubt during his prayer, let him prostrate twice after he said the taslim." (Using translation from Nasāʾī 1250)   

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ شَكَّ فِي صَلاتِهِ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ  

[Machine] The Prophet ﷺ said, "Whoever forgets a portion of their prayer should perform two prostrations while sitting."  

أَنَّ النَّبِيَّ ﷺ قَالَ «مَنْ نَسِيَ مِنْ صَلَاتِهِ شَيْئًا فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ»  

[Machine] The Prophet ﷺ said, "Whoever forgets something from their prayer, they should perform two prostrations (sujood)."  

أَنَّ النَّبِيَّ ﷺ قَالَ «مَنْ نَسِيَ شَيْئًا مِنْ صَلَاتِهِ فَلْيَسْجُدْ سَجْدَتَيْنِ»  

[Machine] The Prophet ﷺ said, "Whoever has doubt about something in his prayer, let him perform two prostrations as long as he did not finish with the salaam."  

أَنَّ النَّبِيَّ ﷺ قَالَ «مَنْ شَكَّ فِي شَىءٍ مِنْ صَلَاتِهِ فَلْيَسْجُدْ سَجْدَتَيْنِ مَا لَمْ يُسَلِّمْ»  

[Machine] If one forgets a prayer, they should perform it as soon as they remember, then make two prostrations while sitting.  

أَنَّهُ نَسِيَ مِنْ صَلَاتِهِ فَلْيُصَلِّهِ ثُمَّ يَسْجُدُ سَجْدَتَيْنِ وَهُوَ جَالِسٌ  

"مَنْ نَسِيَ شَيئًا مِنْ صَلاتِهِ فَليَسجُدْ سَجْدَتَينِ وَهُوَ جَالِس".