Yahya related to me from Malik that he had heard that Abdullah ibn Umar would use the animal he was riding as a sutra when he prayed.  

أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ كَانَ يَسْتَتِرُ بِرَاحِلَتِهِ إِذَا صَلَّى  

Yahya related to me from Malik from Hisham ibn Urwa that his father used to pray in the desert without a sutra.  

أَنَّ أَبَاهُ كَانَ يُصَلِّي فِي الصَّحْرَاءِ إِلَى غَيْرِ سُتْرَةٍ