During the reign of al-Mansur (r. 754–775), Musa was appointed on multiple occasions as governor of the Jazira and Mosul.[3] While there he enacted severe taxation policies which led to widespread unrest and earned a lengthy condemnation of his activities in the Chronicle of Pseudo-Dionysius of Tell-Mahre.[4] Al-Mahdi nevertheless returned him to the same post in 783–784, during which he carried out the caliph's plans to construct an enlargement of the Friday mosque in Mosul.[5]