(12) باب مَنْ تَطَوَّعَ فِي السَّفَرِ فِي غَيْرِ دُبُرِ الصَّلَوَاتِ وَقَبْلَهَا
Narrated `Abdullah bin Amir that his father had told him that he had seen the Prophet (p.b.u.h) praying Nawafil at night on the back of his Mount on a journey, facing whatever direction it took.
Reference: Sahih al-Bukhari 1104
In-book reference: Book 18, Hadith 24
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 20, Hadith 207