This book, which became famous under the title "Al-Jawab Al-Kafi liman arad al-Dawa al-Shafi", and was also printed under the name "Al-Da' wa al-Dawa'", is one of the most beneficial books for refining souls, stirring them towards abstaining from sins, and sincere repentance. It was specifically dedicated to addressing one of the most dangerous diseases of the hearts, different from other diseases in its nature, causes, treatment, and when it is managed and its remedy is well-established, it exhausts the patient. This disease is the ailment of love, as expressed by the poet: "Love is a chronic disease with no cure, confounding even the skilled physicians." The author, may Allah have mercy on him, was among the skilled physicians of the hearts who did not resort to the wisdom of the Greeks in treating heart diseases, but rather derived their remedies from the Book of Allah, the Wise, which contains guidance, admonition, and healing for what is in the hearts, and from the Sunnah of the Messenger of Allah, who was sent to teach people the Book and wisdom, reform their beliefs and behavior, purify their souls, and guide them to the right path. The community that emerged under his guidance was the best nation brought forth for mankind, unparalleled in human history. The origin of the book was a consultation and a response to the author's inquiry about a man afflicted with a disease that, if it persisted, would ruin his worldly and hereafter life, despite his efforts to rid himself of it through various means, only to worsen it. The respondent observed the severity of the situation and the severity of the affliction, thus considering that elaboration was more appropriate than brevity in this case. Advising the questioner and showing compassion towards him and others like him necessitated delving into the causes of the disease and its dire consequences, and guiding towards prevention methods and ways of salvation. Therefore, the respondent wrote valuable chapters on supplication, the conditions for its acceptance, hindrances preventing its effectiveness, the difference between having good expectations of Allah and being deluded by His mercy, the harms of sins and their effects on the lives of individuals and nations, their punishments in this world and the hereafter, the reality of worshiping Allah alone and associating partners with Him, the secret behind why polytheism is not forgiven, resisting the allure of images for the sake of monotheism, and its immediate and future harms. Thus, the response to that question became an elaborate book. While the society in which the author, may Allah have mercy on him, lived was in need of this book due to its adherence to religion and preservation of morals and manners, our societies are even more in need of it today as they are plagued by corruption. The tempters have succeeded in many Islamic countries in luring Muslim women under deceptive slogans to remove the hijab and mix with men, making what is good known as evil, and what is evil known as good. The brethren of the devils have excelled in finding new ways to provoke sexual desires and spread obscenity. They knew that moral decay is the fastest way to destroy the nation, and Allah is the One we seek help from.