During the governorship of al-Hajjaj ibn Yusuf over Iraq, Salih entered the dīwān (bureaucratic administration) of Basra under the mentorship of the Persian Zoroastrian administrator Zadhanfarrukh. At the time, the language of bureaucracy in Iraq and the eastern half of the Caliphate was Persian. Unlike Zadhanfarrukh, Salih was fluent in Arabic as well as Persian, due to his Muslim upbringing in Basra.