The book of Sharia was written by Imam Al-Ajurri, who died in the year 360 AH. One of the reasons for Imam Al-Ajurri writing this book was the spread of innovations and whims in his time, and the emergence of deviant sects hostile to the people of the Sunnah and the community, to the point that these sects confused many people about their religion and their doubts about the principles of their belief, and they began to raise doubts about them and argue with them about ambiguous matters. So Imam Al-Ajurri wrote this book out of zeal for the religion and the correct and pure belief, as Imam Al-Ajurri said about the reason for writing this book: “I have outlined in this book - which is the book of Sharia - from its beginning to its end what I know that everyone who is included in Islam is in need of its knowledge due to the corruption of the doctrines of many people, and because many deviant whims and successive innovations have appeared, what I know that the people of truth strengthen their souls with it, and it suppresses the people of innovation and misguidance according to what God Almighty taught me, so praise be to God for that.”
The book addresses most of the issues of Islamic doctrine according to the approach of the righteous predecessors. It also addresses the refutation of the innovators and deviant sects. Among these issues are the issues of faith and disbelief, in which the Khawarij and Mu'tazila sects deviated on the one hand, and the Jahmites and Murji'ites on the other. Among them were the issues of the Names and Attributes, and the issue of the Qur'an being the Word of God took up a large area of ​​research due to the tribulation of the ordeal that some of the Abbasid caliphs caused. It was one of the most dangerous innovations that afflicted broad sectors of the Ummah until God Almighty facilitated its elimination by His grace at the hands of the Imam of the Sunnis, Ahmad ibn Hanbal (may God have mercy on him), and those who followed him in the truth. Among these issues were also the issues of divine predestination and destiny, in which the Qadarites and Jabrites deviated, while the Sunnis took a middle ground between all these sects. The issue of belief in the Companions, the Imamate, and the Ahl al-Bayt (the Prophet) was also one of the most important issues that distinguished the Sunnis from the misguided Rafidite sects. This book examines and explains these major issues with clear chains of transmission, arguments, and evident proofs that clearly demonstrate to anyone who learns the features of this approach—the pure and unadulterated approach of Islam as brought by the Prophet (peace and blessings of God be upon him).