The book of the reasons for the descent of its author, Abi Al -Hassan Ali bin Ahmed bin Muhammad bin Ali Al -Wahidi, Al -Nisaburi, Al -Shafi'i (deceased: 468 AH), is one of the books that were concerned with mentioning the reasons for the descent of the verses of the Noble Qur'an, and one of the first books that were classified in this section. His author mentioned the reasons for the revelation of the verses of the Qur'an with its chain of transmission to the Companions, and without them from the followers and other interpreters, and sometimes he recites their statements without mentioning the chain The revelation of the verses of the Holy Quran