In 784 Musa was appointed governor of Egypt with jurisdiction over both its military and taxation affairs, and with the task of quelling the ongoing rebellion of Dihyah ibn Mus'ab in Upper Egypt. Within a short time of his arrival he seriously alienated a large segment of the population with his large tax increases, including a doubling of the tax on the faddan and imposing levies on the markets and beasts of burden, and his standing was further harmed after he was accused of accepting bribes. In response, the Qays and Yemen Arabs of the Hawf district united against him and proclaimed a war of resistance, while the infuriated members of the Fustat jund for their part formed a secret pact with the Hawfis to not fight against them.