This book attempts to be a window into the Sunnah from different aspects. By shedding light on the types of sciences of the Sunnah of the Chosen One, may God bless him and grant him peace. This book is an invitation to seekers of knowledge. To focus on the sciences of the Sunnah, which have not been simplified to the people, but are still limited to specialists. Among them are the reasons why the schools of thought differ in understanding it. The type of rules emerging from this Sunnah are fundamental rules and their difference from jurisprudential rules. The miracle is in maintaining the validity of the Sunnah, despite the distance of time. This Sunnah is facilitation and mercy for people.