وأمضى المعتصم الأفشين خيذر بن كاوس إلى سروج، وأمره بالبروز منها والدخول من درب الحدث
Al-Mu'tasim sent al-Afshin Khaydhar b. Kawus to Saruj and instructed him to start out from there and enter (the Byzantine territory via the pass (darb) of al-Fladath, specifying for him a day when he was to enter it