It is related that Muhammad was traced out on one day in Sarha by the Abbasid agent, named Muhammad bin Ali al-Khorasani, who surprised the Imam in a mosque. He was greatly impressed to behold the Imam, and lost courage to arrest him, and permitted the Imam to escape. Thence, Muhammad went to Azar in Khuzistan, a province of south-western Iran. It was bounded on the west by the Iran-Iraq border; on the north by Luristan, on the south by the Persian Gulf; and on the east by the river Hindiyan. Muhammad thence proceeded to Shapur. Disguised as a merchant, he stayed in Shapur with a certain Qamas bin Nuh, whose daughter Rabta, he married. Shapur (Arabic Sabur), the Shapurgird of Firdusi; became an unscathed place for the Imam for some times.