Ibn ‘Asakir’s (1105-1176) al-Arba‘in Hadithan fi al-hathth ‘ala al-jihad (Forty Hadiths for Inciting Jihad), commissioned by his patron Sultan Nur al-Din, has survived in a unique manuscript. Based on a close examination of the manuscript’s eleven colophons and two ownership notes, this paper will demonstrate that Ibn ‘Asakir’s Forty Hadiths was taught to a large number of individuals in important Damascene schools and the Umayyad Mosque between 1170 and 1318. Several of these individuals were counted among the most significant scholars of the city when they attended these teaching sessions; others would be counted among their number later in life. Some of the colophons mention children who were brought by their fathers to hear a reading of the Forty Hadiths and receive a license (ijaza) to teach and transmit the text when they grew up and became scholars; one of these children was a five year old girl! It is noteworthy that the colophons and dates of teaching sessions 3 and 4–9 of the Forty Hadiths, held in 1221 and 1227–1230 at different important locations in Damascus, coincide with the Fifth Crusade and the Crusade of Frederick II, respectively. These teaching sessions demonstrate that Ibn ‘Asakir’s Forty Hadiths was not taught simply for the purpose of scholarly curiosity; rather, it was instrumental for the preaching of jihad as a direct response to renewed Crusader challenges well into the Ayyubid period when the local Sunni political and religious establishments were eager to rally the Damascene Sunni population time and again to fight new waves of Crusaders.