The first extant investiture letter for a ṣāḥib al-shurṭa can be found in a compendium of the rasāʼil (government letters) written by the head of the Buyid chancery in Baghdad, Abū Isḥāq Ibrāhīm al-Ṣābiʾ (d. 384/994). This letter was written for an official appointed as the ṣāḥib al-shurṭa over the city of Wāsiṭ in Iraq during the reign of the Buyid amir of Iraq, ʿIzz al- Dawla (r. 356-367/967-978). The text gives rare insight not only into the investiture genre for the shu …
This invesiture letter along with other rasāʼil were edited by Iḥsān Dhūnūn al-Thāmirī in Diwān Rasāʾil al-Ṣābiʾ: the Registry of al-Ṣābiʾ Letters. London: Al-Furqān Islamic Heritage Foundation, 2017. A scan of this investiture letter from Volume 1 has been made available.