Hadith of the Quran and Sunnah Hadith of the Quran and Sunnah Several hadith (oral tradition about the words and deeds of the Islamic prophet Muhammad) indicate the importance as sources of Islam not only the Quran (the revelation of God to Muhammad, infallible but containing compressed information), but also of the Sunnah of the Islamic prophet Muhammad (a detailed explanation of the everyday application of the principles established in the Qur'an that is based on ahadith). One of these hadith quotes Muhammad as saying: "I have left among you two matters by holding fast to which, you shall never be misguided: the Book of God
Introduction to the Science of Hadith category, which comprises 21 types, relates to the names of the narrators. This includes the definition of a "ṣaḥābī" (companion), a "tābi`ī" (follower), the time periods of narrators, names and paidonymics among others. Later scholars included additional types of hadith in their own works, with some almost reaching 100. The "Introduction" became the basis for subsequent books in hadith terminology. A number of subsequent scholars followed Ibn al-Ṣalāḥ in the ordering of his book, including al-Nawawī, Ibn Kathīr, al-ʻIraqi, al-Bulqīnī, Ibn al-Jamā`ah, al-Tabrīzī, al-Ṭībī and al-Zirkashī. In many instances this influence was direct, with numerous scholars authoring books indicating its