It was narrated from ‘Abdur-Rahman Al-A’raj that Ibn Buhainah told him that the Prophet ﷺ stood up in the second Rak’ah of Zuhr and forgot to sit. When he had finished his prayer, and before he said the Salam, he performed the two prostrations for forgetfulness (Sahw) and said the Salam.  

أَخْبَرَهُ أَنَّ النَّبِيَّ ﷺ قَامَ فِي ثِنْتَيْنِ مِنَ الظُّهْرِ نَسِيَ الْجُلُوسَ حَتَّى إِذَا فَرَغَ مِنْ صَلاَتِهِ إِلاَّ أَنْ يُسَلِّمَ سَجَدَ سَجْدَتَىِ السَّهْوِ وَسَلَّمَ  

[Machine] "He informed him that the Messenger of Allah ﷺ stood for two units of Dhuhr prayer without sitting down. After completing his prayer, he prostrated two prostrations and then he gave the salutation."  

أَخْبَرَهُ «أَنَّ رَسُولَ اللَّهِ ﷺ قَامَ فِي ثِنْتَيْنِ مِنَ الظُّهْرِ فَلَمْ يَجْلِسْ فَلَمَّا قَضَى صَلَاتَهُ سَجَدَ سَجْدَتَيْنِ ثُمَّ سَلَّمَ بَعْدَ ذَلِكَ»  

[Machine] "The Messenger of Allah ﷺ stood up in the two units of prayer and did not sit until he finished his prayer. Then he prostrated twice, and then he made the salutation."  

«أَنَّ رَسُولَ اللهِ ﷺ قَامَ فِي الرَّكْعَتَيْنِ مِنَ الصَّلَاةِ فَلَمْ يَقْعُدْ حَتَّى فَرَغَ مِنْ صَلَاتِهِ ثُمَّ سَجَدَ سَجْدَتَيْنِ ثُمَّ سَلَّمَ»  

"أَنَّ رَسُولَ الله ﷺ قَامَ فِى اثْنَتَيْن منَ الظُّهْرِ، نَسِىَ الْجُلُوسَ، حَتَّى إِذَا فَرَغَ منْ صَلَاتهِ إِلَّا أَنْ يُسَلِّمَ، سَجَدَ سَجْدَتَى السَّهْو، وَسَلَّمَ".