Language:
كتاب الأذان
10  
Call to Prayers (Adhaan)
(146)
Chapter: Whoever considered that the first Tashah-hud is not compulsory
(146)
باب مَنْ لَمْ يَرَ التَّشَهُّدَ الأَوَّلَ وَاجِبًا لأَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَامَ مِنَ الرَّكْعَتَيْنِ وَلَمْ يَرْجِعْ
Sahih al-Bukhari 829

Narrated `Abdullah bin Buhaina:

(he was from the tribe of Uzd Shanu'a [??] and was the ally of the tribe of `Abdul-Manaf and was one of the companions of the Prophet): Once the Prophet (ﷺ) led us in the Zuhr prayer and stood up after the second rak`a and did not sit down. The people stood up with him. When the prayer was about to end and the people were waiting for him to say the Taslim, he said Takbir while sitting and prostrated twice before saying the Taslim and then he said the Taslim."

حَدَّثَنَا أَبُو الْيَمَانِ، قَالَ أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ حَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ هُرْمُزَ، مَوْلَى بَنِي عَبْدِ الْمُطَّلِبِ ـ وَقَالَ مَرَّةً مَوْلَى رَبِيعَةَ بْنِ الْحَارِثِ ـ أَنَّ عَبْدَ اللَّهِ ابْنَ بُحَيْنَةَ ـ وَهْوَ مِنْ أَزْدِ شَنُوءَةَ وَهْوَ حَلِيفٌ لِبَنِي عَبْدِ مَنَافٍ، وَكَانَ مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم‏.‏ أَنَّ النَّبِيَّ صلى الله عليه وسلم صَلَّى بِهِمُ الظُّهْرَ فَقَامَ فِي الرَّكْعَتَيْنِ الأُولَيَيْنِ لَمْ يَجْلِسْ، فَقَامَ النَّاسُ مَعَهُ حَتَّى إِذَا قَضَى الصَّلاَةَ، وَانْتَظَرَ النَّاسُ تَسْلِيمَهُ، كَبَّرَ وَهْوَ جَالِسٌ، فَسَجَدَ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ ثُمَّ سَلَّمَ‏.‏
Reference : Sahih al-Bukhari 829
In-book reference : Book 10, Hadith 223
USC-MSA web (English) reference : Vol. 1, Book 12, Hadith 792
  (deprecated numbering scheme)