وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، أَنَّ أَبَاهُ، كَانَ يُصَلِّي فِي الصَّحْرَاءِ إِلَى غَيْرِ سُتْرَةٍ ‏.‏

Yahya related to me from Malik from Hisham ibn Urwa that his father used to pray in the desert without a sutra. Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 375
Web Ref:  Muwatta Imam Malik Book 9 Hadith 44