Sheikh-e Sadūq, Abū Ja'far, Muhammad son of Ali son of Husain son of Bāb-e Weyh-e Qummī (305-381 H.), one of the outstanding Shiite Jurisprudents (Faqīhs) and Narrators of the fourth century Hegira.
This book gives a collection of Riwāyāt (Narrations/ Traditions) attributed to the Holy Prophet (S.A.) and the Immaculate Imams (A.S.) concerning the philosophy and origins of some of religious precepts and Islamic Injunctions. Sheikh-e Sadūq indicates also the original grounds for some specific names of the divine prophets and the reasons behind certain acts of the prophets, or those of the prophet of Islam (S.A.) and the infallible Imams (A.S.)
Sheikhe Sadūq who himself is a distinguished Shiite narrator, spent his lifetime in listening to, recording and quoting the Traditions of Ahl-ul Bayt (A.S.), so that he could convey the sayings to others and the posterity. By writing this book he presented a great service towards introducing Islamic teachings and explaining the motives and reasons behind the Islamic commandments.
This and other books of Sheikh-e Sadūq have been acknowledged by the Shiite Jurisprudents (Ulamā) as the most credible principal sources of narrations of the Shiite. Sadūq's narrations are quoted in the collections of major Shiite reference books of Traditions like Bihār-ul Anwār, Wasā'il-ush-Shi'a, as authentic ones. Ilal-ush-Sharāye' is one of the authentic books of narrations, which Shiite Ulamā included it in their authorizations (Ijāzāt).
The scope ranges from explaining the raison d'tre of the Islamic precepts as well as the philosophy behind them, to matters of detail such as the reason why it is incumbent upon Believers to offer Salāt' (prayer), and why the Zuhr (noon) & Asr (afternoon) prayers, as well as Maghrib (sunset) & Ishā (night) prayers can be accomplished successively without intervals.
The discussions, too, are varied. Some concerning the Islamic beliefs and ideas include such questions as to why prophets are superior to angels and as to why we do need the prophets and the Imams (A.S.). Also some historical matters are documentarily evidenced, like the sacred Saturday prohibitions for hunting observed by the Jews, as well as explanation of the reason for nighttime burial of Hazrat-e Fātimah Zahrā (S.A.), among other useful subjects.
On the whole, this book is all the more valuable for its narrations from the Ahl-ul Bayt (A.S.) which pinpoint the singular way to one's acquisition of Islamic teachings and precepts.
Allāmah Majlisī has commented: "The books of Sheikh-e Sadūq are of the same importance of Kutub-e Arba-ah' (the four significant reference books of Shi'a). Sadūq's books are included among the books authorized by the great Shiite Mashāyekh' (senior Ulamā). Many of the Shiite Ulamā and Jurisprudents quote Traditions from his books. By God's Grace, we do have all manuscripts and the proofread copies of the Traditions at our disposal."
Āqā Buzurg Tehrāni says: "The book Īlal-ush-Sharāye' wal-Ahkām' was written by Sheikh-e Sadūq, Abū Ja'far Muhammad son of Ali son of Mūsā son of Bāb-e Weyh-e Qummī. This book has been summarized by Sheikh Ibrāhīm Kaf'amī in his work Ikhtesār Īlal-ush-Sharāye', and by Sheikh Sharafuddīn Yahyā Bahrānī in his book entitled as Talkhīs Īlal-ush-Sharaye'. Furthermore, Āqā Najafī, Sheikh Muhammad Taqī Isfahāni translated the book into Persian language."
Some of the topics in this book are as follows: circumstance of marriage of the children of Hazrat-e Ādam (A.S.) with angels, the reason for participation of Hazrat-e Ali (A.S.) in the High council, why the morning prayer should be voiced, the philosophy of Zakāt, why a person's bequest (to be spent as an act of charity - for himself after his death) should be rightly confined to one-third of his assets, why a physician is called or named a Tabīb', why the meat of wild animals are Harām (religiously unlawful to eat), and many other useful and valuable topics.