works The earliest and the most important work in this genre is undoubtedly Kitab asbab al-Nuzul ("Book of occasions of revelation") of Ali ibn Ahmad al-Wahidi (d. 1075 CE). al-Wahidi mentions occasions of about 570 verses out of 6236 verses of the Quran. Wahidi's work is not only the first attempt to collect all the material regarding the occasions of revelation in one single volume, but it is also the standard upon which all subsequent works were based. al-Wahidi was born in the city of Nishapur and he died there at an advanced age. He was a poet, philologist, grammarian and Quranic commentator. In fact, He was considered a great commentator of the Quran of his time. His main teacher was the famous Quranic commentator al-Thalabi (d. 1036 CE) and Wahidi seems to have enjoyed the support of the Seljuq vizier Nizam al-Mulk. Another important work is by al-Suyuti (d. 1505 CE) which is a slight improvement of al-Wahidi's book. Suyuti wrote his book about four centuries after al-Wahidi. It contains more occasions of revelation compared to Wahidi's work. His work covers 102 chapters (sura) of the Quran while Wahidi's work covers 83 suras. The name of his book is Lubab al-Nuqul fi Asbab al-Nuzul (meaning "The best of narrations concerning the circumstances of revelation"). No asbāb works from earlier than the 11th century are known, and it is unlikely that this genre of exegetical literature existed before then. Though there is a section titled Nuzūl al-Qur'ān in Ibn al-Nadīm's 10th-century bibliographical catalog Kitāb al-Fihrist (including one Nuzūl al-Qur'ān attributed to the semi-legendary Ibn 'Abbās as transmitted through 'Ikrima), there is no evidence to believe that most of these works ever existed, or that their ambiguous titles signify texts within the asbāb al-nuzūl genre. In Rippin's detailed examination of pre-18th-century exegetical literature, other works include as follows: Asbāb al-nuzūl wa qisas al-furqāniyya by Muhammad ibn As'ad al-'Irāqī (died 1171). Contains sabab reports mixed with qisas al-anbiyā (stories of the prophets) material. The former seem independent of al-Wāhidī's compilation and are isnad-less. Exists in two manuscripts copies, one at the Chester Beatty Library (Manuscript 5199). A manuscript (Berlin Staatsbibliothek, Catalog no. 3578). ascribed to al-Ja'barī, probably pseudepigraphicaly. Consists of sabab and naskh material interspersed, with the former containing very abbreviated isnads where only the first authority is listed. According to its final page this manuscript was written in 1309. Though al-Wāhidī