The Muhallabite tradition which represents the appointment as distasteful to _H_ajjāj but popular in Khurāsān is almost certainly influenced by the later hostility between Yazīd and _H_ajjāj. It is probable, however, that _H_ajjāj, whose policy was to keep his governors dependent on himself, viewed with suspicion the concentration of authority in the hands of the leader of a powerful hostile clan, but he was content to wait for the meantime and give Yazīd sufficient rope to hang himself. Except for an attempted raid on Khwārizm Yazīd carried out no expeditions, while under his government the precarious internal balance of Khurāsān was soon upset. The quarrels of Qays had been composed by Muhallab, but they were in no mood to bear with the leadership of the parvenu Azd; already before the death of Muhallab, in spite of the Tamīmite eulogy quoted by _T_abarī, there was a moment when the feud threatened to break out. The pronounced factional leanings of Yazīd strained the situation still further. Even more serious was the attitude of the mawālī. _H_urayth, the brother of Thābit ibn Qu_t_ba, had been left behind at Kish by Muhallab to collect the tribute, but on his return was scourged for disobedience. The disgrace cut _H_urayth deeply; too late Muhallab realised the gravity of his act, but _H_urayth spurned his overtures and with Thābit fled to Mūsā at Tirmidh. Yazīd retaliated with foolish severity by maltreating their families, which only inflamed the general resentment. _H_urayth and Thābit used their influence to stir up an insurrection to act in concert with Mūsā; the king of Chaghāniān and his Ephthalite confederates headed by Nēzak, prince of Bādghīs, readily responded, while Persian interest was excited by the return to _T_ukhāristān of the son of Pērōz, the heir of the Sāsānids. It seems probable that even some of Qays were a party to the scheme[38]. Seizing an opportunity when Yazīd was occupied with the rebel forces of Ibn al-Ashath on the borders of Khurāsān the revolt broke out. Yazīd was powerless to prevent the expulsion of his residents from Chaghāniān and Lower _T_ukhāristān, and Mūsā is said to have refrained from invading Khurāsān only from fear that it would fall into the hands of Thābit and _H_urayth. Even the success claimed for Yazīd in Bādghīs can have been of little effect[39]. Fortunately for the Arabs, Mūsā’s jealousy of Thābit and _H_urayth caused a division in the ranks of their enemies, but though the brothers both fell in battle, the danger remained acute. The son of Pērōz still lingered in _T_ukhāristān, and even at Damascus there was some uneasiness about the situation in Khurāsān[40].