Al-Khiṣāl
Shaykh al-Ṣadūq (d. 381/991) arranged this one entirely by number: traditions enumerating one thing, then two, then three, ascending through the book. The ordering is a memory device rather than a subject index — it is how material was held before it could be looked up — so a chapter moves from the three things that ruin a person to the three that save him. The effect is to put unrelated material side by side, spanning ethics, law, cosmology and history. It preserves a great deal found nowhere else, including the long treatise on rights attributed to Imam Zayn al-ʿĀbidīn.
Parts
About this collection
Al-Khisal
Al-Khisāl (which means the Traits), is collection of hadith compiled by Muhammad b. Husayn b. Babawayh al-Qummī known as Shaykh al-Sadūq (d. 381 AH). He is considered one of the greatest Shī’ī jurists (faqīh) and hadith transmitters in the 4th Islamic century. Al-Sadūq has compiled many books, among them Man lā yahduruh al- faqīh – second of the Four Canonical Shī’ī hadith books (al-kutub al-arba‘ah). He travelled extensively to collect traditions. By stressing on traditions, he explained and proved theological arguments. His jurisprudence was also based on traditions.
Al-Khisāl is an encyclopedia of Islamic knowledge. It mentions historical, exegetical, philosophical, and political subjects. The author has categorized the hadith based on the numbers in every hadith. The book is unique and is the first book written in this manner. It covers numbered characteristics, starting with one and ending with one million. The traditions are presented with a complete record of transmission.
The title of each chapter is according to numbers: the hadiths containing one trait are in chapter one; the hadiths containing two traits are in chapter two, and so on. For example: Chapter One has, ‘One sign of the affection for the world’, Chapter Two, ‘Two characteristics of a Shī‘ah’, Chapter three, ‘Three characteristics which have to be in a person to be a faithful’, and so on.
Shaykh Sadūq himself presented his motivation for compiling Al-Khisal as follows, ‘I noticed that the previous Shaykhs and scholars have already compiled books on various aspects of knowledge. However, they have neglected to compile a book on numbers and good and bad characteristics. Since this topic is especially useful for those who seek knowledge, I decided to compile this book in order to get closer to God, attain divine rewards, prosperity and the Almighty God’s Mercy. I ask God not to turn my hopefulness into hopelessness, since He has power over all things'.
Reference: https://en.wikishia.net/, https://www.al-islam.org/al-khisal-numeric-classification-traditions-characteristics-shaykh-saduq/preface