This is one of the best and oldest book written on Sufism nearly 950 years ago. It has the saying, methods and rules of the Sufis and the stories of Ahle Sufa, Shaba, Ahle Bayt, Ancient Imams and leading Sufi saints of the early ages whose lives were lived according to Quran and Sunnah. Data Saab discusses the various schools of Sufism, the correct beliefs of Muslims, Conduct, Hadiths and Quranic Tafsir etc. In this way it is a complete book where Islamic teachings are given in such an easy way that from student to saint everyone can benefit. Data Saab proves that Sufis are only those who follow Quran and Sunnah and that Tariqat is no different from Shariah but the Tariqat is the fruit and the end result of shariah, and these two cannot be separated at all. He also refutes the false and fabricated Sufi tales which corrupt people and reminds that we follow the true Sufi examples at all times.
Kashf-ul-Mahjub is such a great book that it opens one's heart to the Spiritual Realities and one can easily understand that Sufism is the true Islamic teachings. After reading the book, one finds that his mind, heart and thoughts gets new form of Love, Wisdom and Knowledge that no other book on Sufism provides. Data Saab himself says in this book that people should regard this book, in terms of reading it and benefiting from it. One can surely realize after reading the book ho great is Hazrath Syed Ali Hujwiri's blessed knowledge, Marifat, Tariqat, Haaqah and Waliyaat, given to him by Allah Tala.
Analysis and Rank
His book hold dominant position in the world of Sufism and it is written in Persian language. This book represents the Sufi theories such as Marifat, Tariqat, Haaqah and Waliyaat in such a way that they reflect the needs of every age. For example, this book was useful early 900 years ago, was useful 500 years ago and is useful today and will be useful for as long as Allah want it to be. Hazrat Nizamuddin Awliya says that:
Oh Student of Sufism, May Allah give the bounty of both the worlds and he further writes,By writing this book (Kash al-Mahjub) my aim is that if someone has this book then there shouldn't be a need to obtain any other book as I have said in the beginning and your third question of this book that this book will be sufficient for the Students of Sufism.