3; v. 34: p. 107, etc., consistently refers to Ishaq as "Ishaq ibn Ibrahim ibn al-Mus'ab," leading some scholars (for example Le Strange 1900, p. 119) to refer to him as a cousin of 'Abdallah's father Tahir ibn al-Husayn. ↑ Al-Tabari 1985–2007, v. 32: pp. 129, 135; Al-Ya'qubi 1883, p. 574; Turner 2006, p. 402. ↑ Al-Tabari 1985–2007, v. 32: pp. 146, 182; Al-Ya'qubi 1883, p. 565. ↑ Ibn al-'Adim 1996, p. 40. ↑ Al-Tabari 1985–2007, v. 32: pp. 184, 189. ↑ Al-Tabari 1985–2007, v. 32: pp. 199 ff.; Al-Ya'qubi 1883, pp. 576–77; Hinds 1993, pp. 2–3. ↑ Bosworth 1993, p. 776. An anecdotal example of the close relationship between al-Mu'tasim and Ishaq is provided in Al-Tabari 1985–2007, v. 33: pp. 212 ff. ↑ Al-Tabari 1985–2007, v. 34: p.