Sahih Bukhari
Sahih Bukhari Volume 002, Book 020, Hadith Number 199.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 20. Shortening The Prayers (At-Taqseer)
Narated By Jabir bin 'Abdullah : The Prophet used to offer the Nawafil, while riding, facing a direction other than that of the Qibla.