(7) باب صَلاَةِ التَّطَوُّعِ عَلَى الدَّوَابِّ وَحَيْثُمَا تَوَجَّهَتْ بِهِ
Narrated `Abdullah bin 'Amir from his father who said:
I saw the Prophet (p.b.u.h) offering the prayer on his mount (Rahila) whatever direction it took.
Reference: Sahih al-Bukhari 1093
In-book reference: Book 18, Hadith 13
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 20, Hadith 198