Narrated Said bin Yasar:
I was going to Mecca in the company of 'Abdullah bin 'Umar and when I apprehended the approaching dawn, I dismounted and offered the Witr prayer and then joined him. 'Abdullah bin 'Umar said, "Where have you been?" I replied, "I apprehended the approaching dawn so I dismounted and prayed the Witr prayer." 'Abdullah said, "Isn't it sufficient for you to follow the good example of Allah's Apostle?" I replied, "Yes, by Allah." He said, "Allah's Apostle used to pray Witr on the back of the camel (while on a journey)."