The great scholar of the eighth century Al-Buqâ'î said of this work: “It is a very useful book, of great value, containing many lessons. Nothing equivalent to it has been composed. And it is so rich that it is highly unlikely that you will find what it contains in another book. Indeed, the topics covered are of interest that is not the least. The soul is a subject that has always fascinated all those who wonder about the afterlife. However, given that this falls under the invisible, and therefore, the domain of belief, everything that the Muslim must believe on this subject cannot (and must not) find its source only in the texts of the Koran and the authentic sunnah .