Dāwūd b. al-Muḥabbar, Abū Sulaymān al-Ṭāʾī (d. 8 Jumādā I 206/9 October 821), a traditionist (muḥaddith) known not only for his asceticism (zuhd) but also for his book Kitāb al-ʿaql.
He originally came from an Iranian family, and his grandfather is reported to have been a client (mawlā) who was taken as a prisoner of war from Iṣfahān (see Abū Nuʿaym, Dhikr, 2/165; cf. Ibn Māja, 2/929 for a ḥadīth attributed to Dāwūd about the virtues of Qazwīn). Apparently his father lived in Baṣra (see also Abū Nuʿaym, Ḥilyat, 6/233), which was where Dāwūd grew up (al-ʿUqaylī, 2/35). For some time…