Musannaf Ibn Abi Shayba 3:355

Abu Bakr narrated to us, he said: Hafs narrated to us, from al-Hasan ibn Ubayd Allah, he said: I saw al-Aswad praying in a hooded cloak (burnus) of Taylasan, prostrating in it. And I saw Abd al-Rahman, meaning ibn Yazid, praying in a Syrian hooded cloak (burnus), prostrating in it.