Pre-Islamic Arabia
Daif would later author more than 50 works in arts and literature. His study of the development of Arabic poetry during the Umayyad Caliphate is still considered to be the most important reference book on the topic. His great work was his 100-volume "History of Arabic Literature", a project that took 30 years to complete, and was an overview of all poetry, literary criticism and rhetorical studies from Pre-Islamic Arabia up to the post-Abbasid era. The work is considered indispensable for students of Arabic literature, and some volumes have been reprinted up to 20 times.