Language:
كتاب الحج
25  
Hajj (Pilgrimage)
(27)
Chapter: The praising and glorification of Allah and saying Takbir before Talbiya, while mounting animal
(27)
باب التَّحْمِيدِ وَالتَّسْبِيحِ وَالتَّكْبِيرِ قَبْلَ الإِهْلاَلِ عِنْدَ الرُّكُوبِ عَلَى الدَّابَّةِ
Sahih al-Bukhari 1551

Narrated Anas bin Malik:

Allah's Messenger (ﷺ) offered four rak`at of Zuhr prayer at Medina and we were in his company, and two rak`at of the `Asr prayer at Dhul-Hulaifa and then passed the night there till it was dawn; then he rode, and when he reached Al-Baida', he praised and glorified Allah and said Takbir (i.e. Al hamdu-li l-lah and Subhanallah(1) and Allahu-Akbar). Then he and the people along with him recited Talbiya with the intention of performing Hajj and Umra. When we reached (Mecca) he ordered us to finish the lhram (after performing the Umra) (only those who had no Hadi (animal for sacrifice) with them were asked to do so) till the day of Tarwiya that is 8th Dhul-Hijja when they assumed Ihram for Hajj. The Prophet sacrificed many camels (slaughtering them) with his own hands while standing. While Allah's Apostle was in Medina he sacrificed two horned rams black and white in color in the Name of Allah."

حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا وُهَيْبٌ، حَدَّثَنَا أَيُّوبُ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ صَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم وَنَحْنُ مَعَهُ بِالْمَدِينَةِ الظُّهْرَ أَرْبَعًا، وَالْعَصْرَ بِذِي الْحُلَيْفَةِ رَكْعَتَيْنِ، ثُمَّ بَاتَ بِهَا حَتَّى أَصْبَحَ، ثُمَّ رَكِبَ حَتَّى اسْتَوَتْ بِهِ عَلَى الْبَيْدَاءِ، حَمِدَ اللَّهَ وَسَبَّحَ وَكَبَّرَ، ثُمَّ أَهَلَّ بِحَجٍّ وَعُمْرَةٍ، وَأَهَلَّ النَّاسُ بِهِمَا، فَلَمَّا قَدِمْنَا أَمَرَ النَّاسَ فَحَلُّوا، حَتَّى كَانَ يَوْمُ التَّرْوِيَةِ أَهَلُّوا بِالْحَجِّ قَالَ وَنَحَرَ النَّبِيُّ صلى الله عليه وسلم بَدَنَاتٍ بِيَدِهِ قِيَامًا، وَذَبَحَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِالْمَدِينَةِ كَبْشَيْنِ أَمْلَحَيْنِ‏.‏ قَالَ أَبُو عَبْدِ اللَّهِ قَالَ بَعْضُهُمْ هَذَا عَنْ أَيُّوبَ عَنْ رَجُلٍ عَنْ أَنَسٍ‏.‏
Reference : Sahih al-Bukhari 1551
In-book reference : Book 25, Hadith 37
USC-MSA web (English) reference : Vol. 2, Book 26, Hadith 623
  (deprecated numbering scheme)