Abū Salama al-Khallāl, Ḥafṣ (or Aḥmad: Abū Hilāl, 2/98) b. Sulaymān (or Ḥafṣ b. Ghiyāth b. Sulaymān: al-Ṣābī, 129), known as Wazīr Āl Muḥammad (d. Rajab 132/February 750), was one of the major ʿAbbāsid missionaries (dāʿīs) and played a significant part in the overthrow of the Umayyad caliphate.

No details are known about Abū Salama's life prior to his association with ʿAbbāsid missionary activity. Some sources describe him as a client (mawlā) of the Banū Sabīʿ, a branch of the Banū Hamdān (al-Balādhurī, 3/118; al-Ṭabarī, 7/418, 421; Ibn Khallikān, 2/195), while oth…