This book includes a study of the approaches of the authors of the six books of hadith, namely Sahih Bukhari, Sahih Muslim, Sunnah Abu Dawud, Sunnah Abu Dawud, Sunnah al-Nisa'i, Jami' al-Tirmidhi, Sunnah Ibn Majah, Mutta' Malik, Musnad Ahmad, and Musnad al-Darmi, which are the most important books of the Sunnah. These are the most important books that are famous among the books of the Sunnah, and they have received special care and great attention from scholars regarding their contents and men.