Language:
كتاب الحج
25  
Hajj (Pilgrimage)
(146)
Chapter: 'Asr prayer at Abtah on the day of departure from Mina (Day of Nafr)
(146)
باب مَنْ صَلَّى الْعَصْرَ يَوْمَ النَّفْرِ بِالأَبْطَحِ
Sahih al-Bukhari 1763

Narrated `Abdul-Aziz bin Rufai:

I asked Anas bin Malik, "Tell me something you have observed about the Prophet (ﷺ) concerning where he offered the Zuhr prayer on the Day of Tarwiya (8th Dhul-Hijja)." Anas replied, "He offered it at Mina." I said, "Where did he offer the `Asr prayer on the Day of Nafr (day of departure from Mina)?" He replied, "At Al-Abtah," and added, "You should do as your leaders do."

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا إِسْحَاقُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ الثَّوْرِيُّ، عَنْ عَبْدِ الْعَزِيزِ بْنِ رُفَيْعٍ، قَالَ سَأَلْتُ أَنَسَ بْنَ مَالِكٍ أَخْبِرْنِي بِشَىْءٍ، عَقَلْتَهُ عَنِ النَّبِيِّ صلى الله عليه وسلم أَيْنَ صَلَّى الظُّهْرَ يَوْمَ التَّرْوِيَةِ قَالَ بِمِنًى‏.‏ قُلْتُ فَأَيْنَ صَلَّى الْعَصْرَ يَوْمَ النَّفْرِ قَالَ بِالأَبْطَحِ‏.‏ افْعَلْ كَمَا يَفْعَلُ أُمَرَاؤُكَ‏.‏
Reference : Sahih al-Bukhari 1763
In-book reference : Book 25, Hadith 239
USC-MSA web (English) reference : Vol. 2, Book 26, Hadith 816
  (deprecated numbering scheme)