Messenger of Allah ﷺ got up after the second rakʿa of the Zuhr prayer without sitting in between (the second and the third rakʿat). When he finished the prayer he performed two prostrations (of Sahu) and then finished the prayer with Taslim.  

أَنَّهُ قَالَ إِنَّ رَسُولَ اللَّهِ ﷺ قَامَ مِنِ اثْنَتَيْنِ مِنَ الظُّهْرِ لَمْ يَجْلِسْ بَيْنَهُمَا فَلَمَّا قَضَى صَلاَتَهُ سَجَدَ سَجْدَتَيْنِ ثُمَّ سَلَّمَ بَعْدَ ذَلِكَ  

Abdullah bin Buhainah told him that the Messenger of Allah ﷺ stood up following two rak'ahs of Zuhr and did not sit down (for tashahhud). When he finished the prayer he prostrated twice, saying Takbir for each prostration, while he was sitting, before he said the taslim, and the people prostrated with him. (He did that) in place of the sitting that he had forgotten.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَامَ فِي الثِّنْتَيْنِ مِنَ الظُّهْرِ فَلَمْ يَجْلِسْ فَلَمَّا قَضَى صَلاَتَهُ سَجَدَ سَجْدَتَيْنِ كَبَّرَ فِي كُلِّ سَجْدَةٍ وَهُوَ جَالِسٌ قَبْلَ أَنْ يُسَلِّمَ وَسَجَدَهُمَا النَّاسُ مَعَهُ مَكَانَ مَا نَسِيَ مِنَ الْجُلُوسِ  

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  

Yahya related to me from Malik from Yahya ibn Said from Abd ar- Rahman ibn Hurmuz that Abdullah ibn Buhayna said, "The Messengerof Allah ﷺ prayed dhuhr with us and he stood straight up after two rakas without sitting. When he had finished the prayer, he did two sajdas and then said the taslim after that." Malik said, concerning someone who forgot in his prayer and stood up after he had completed four rakas and recited and then went into ruku and then, when he raised his head from ruku, remembered that he had already completed (his prayer), "He returns to a sitting position and does not do any sajda. If he has already done one sajda I do not think he should do the other. Then when his prayer is finished he does two sajdas from the sitting position after saying the taslim."  

أَنَّهُ قَالَ صَلَّى لَنَا رَسُولُ اللَّهِ ﷺ الظُّهْرَ فَقَامَ فِي اثْنَتَيْنِ وَلَمْ يَجْلِسْ فِيهِمَا فَلَمَّا قَضَى صَلاَتَهُ سَجَدَ سَجْدَتَيْنِ ثُمَّ سَلَّمَ بَعْدَ ذَلِكَ  

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. (Using translation from Ibn Mājah 1207)   

أَخْبَرَهُ أَنَّ رَسُولَ اللهِ ﷺ قَامَ فِي الثِّنْتَيْنِ مِنَ الظُّهْرِ نَسِيَ الْجُلُوسَ حَتَّى إِذَا فَرَغَ مِنْ صَلَاتِهِ إِلَى أَنْ يُسَلِّمَ سَجَدَ سَجْدَتَيْنِ ثُمَّ خَتَمَ بِالتَّسْلِيمِ  

[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»  

[Machine] That the Messenger of Allah ﷺ stood during two of the afternoon prayers without sitting in between. After completing his prayer, he prostrated twice and then gave the final salutation.  

أَنَّ رَسُولَ اللهِ ﷺ قَامَ فِي اثْنَتَيْنِ مِنَ الظُّهْرِ فَلَمْ يَجْلِسْ فِيهَا فَلَمَّا قَضَى صَلَاتَهُ سَجَدَ سَجْدَتَيْنِ ثُمَّ سَلَّمَ بَعْدَ ذَلِكَ