Sahih Bukhari 1096

Narrated 'Amir bin Rabi`a: I saw the Prophet on his Mount praying Nawafil by nodding his head, whatever direction he faced, but Allah's Apostle never did the same in offering the compulsory prayers. ..

Narrated Salim: At night `Abdullah bin `Umar used to offer the prayer on the back of his animal during the journey and never cared about the direction he faced. Ibn `Umar said, Allah's Apostle used to offer the optional prayer on the back of his..

Narrated Jabir bin `Abdullah: The Prophet used to pray (the Nawafil) on his Mount facing east and whenever he wanted to offer the compulsory prayer, he used to dismount and face the Qibla. ..

Narrated Anas bin Seereen: We went to receive Anas bin Malik when he returned from Sham and met him at a place called 'Ainat- Tamr. I saw him praying riding the donkey, with his face to this direction, i.e. to the left of the Qibla. I said to him, ..

Narrated Hafs bin `Asim: Ibn `Umar went on a journey and said, I accompanied the Prophet and he did not offer optional prayers during the journey, and Allah says: 'Verily! In Allah's Apostle you have a good example to follow.' (33.21) ..

Narrated Ibn `Umar: I accompanied Allah's Apostle and he never offered more than two rak`at during the journey. Abu Bakr, `Umar and `Uthman used to do the same. ..