His family hailed from the Nahshal branch of the Banu Tamim, which had settled at Marw al-Rudh in Khurasan, probably during the early days of the Muslim conquest of the region.

[3] With the exception of a swift expedition west to retake Ahwaz during the Alid revolt of 762–763, he seems to have remained in Khurasan, where he also faced and defeated the rebellion of Ustadhsis in 768.

[3] Khazim was one of the leading military commanders of the early Khurasaniyya, the Khurasani Arab army that brought and then maintained the Abbasids to power.

[3][4] According to Kennedy, he was a cautious general, but also capable of "quick and surprising decisions" during battle, his favourite tactic being to detach a part of his army to attack the enemy from the rear.

[5] His sons, Abdallah, Ibrahim, Shu'ayb and especially Khuzayma, remained prominent in the Abbasid court after his death, and played a major role in the reign of Harun al-Rashid (r.