كتاب صلاة المسافرين وقصرها
6  
The Book of Prayer - Travellers
(35)
Chapter: Mentioning the recitation of the Prophet (saws) of Surat al-Fath on the day of the conquest of Makkah
(35)
باب ذِكْرِ قِرَاءَةِ النَّبِيِّ صلى الله عليه وسلم سُورَةَ الْفَتْحِ يَوْمَ فَتْحِ مَكَّةَ ‏‏
Sahih Muslim 794 c

This hadlth has been narrated by Khalid al-Harith with the same chain of transmitters (with these words):

(The Holy Prophet) was reciting Surat al-Fath as he was travelling on his mount.
وَحَدَّثَنَاهُ يَحْيَى بْنُ حَبِيبٍ الْحَارِثِيُّ، حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، ح وَحَدَّثَنَا عُبَيْدُ، اللَّهِ بْنُ مُعَاذٍ حَدَّثَنَا أَبِي قَالاَ، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ نَحْوَهُ وَفِي حَدِيثِ خَالِدِ بْنِ الْحَارِثِ قَالَ عَلَى رَاحِلَةٍ يَسِيرُ وَهُوَ يَقْرَأُ سُورَةَ الْفَتْحِ ‏.‏
Reference : Sahih Muslim 794c
In-book reference : Book 6, Hadith 283
USC-MSA web (English) reference : Book 4, Hadith 1738
  (deprecated numbering scheme)