Hadith as Sunna, but it is not necessary that a Sunna would have a supporting hadith sanctioning it. Some sources (Khaled Abou El Fadl) limit hadith to verbal reports, with the deeds of Muhammad and reports about his companions being part of the "Sunnah", but not hadith. Joseph Schacht quotes a Hadith by Muhammad that is used "to justify reference" in Islamic law to companions of Muhammad as religious authorities — "My companions are like lodestars." According to Schacht, (and other scholars) in the very first generations after the death of Muhammad, use of hadith from "Sahabah" ("companions" of Muhammad) and
Introduction to the Science of Hadith al-Ṣalāḥ, in his "Introduction", codified the terminology established by those scholars before him based upon his reading of their works. He did so by citing some of those scholarly statements in the earlier works and deducing from them common terms and definitions in the manner of a scholar authoring a book of "fiqh" (jurisprudence). In this manner, his book was based upon those principles established by the earlier hadith specialists combined with some elements of "fiqh". An example of this would be the inclusion of the division of hadith into "mutawātir" and "āḥād". He therefore only mentioned the statements of