<P> Progress in theory and methodology happened with the coming of the early Muslim jurist Muhammad ibn Idris ash - Shafi ` i (767--820), who codified the basic principles of Islamic jurisprudence in his book ar - Risālah . The book details the four roots of law (Qur'an, Sunnah, ijma, and qiyas) while specifying that the primary Islamic texts (the Qur'an and the hadith) be understood according to objective rules of interpretation derived from scientific study of the Arabic language . </P> <P> Secondary sources of law were developed and refined over the subsequent centuries, consisting primarily of juristic preference (istihsan), laws of the previous prophets (shara man qablana), continuity (istishab), extended analogy (maslaha mursala), blocking the means (sadd al - dhari'ah), custome urf and saying of a companion (qawl al - sahabi). </P> <P> The Quran set the rights, the responsibilities and the rules for people and for societies to adhere to, like not dealing in interest . Muhammad then provided an example, which is recorded in the hadith books, showing people how he practically implemented these rules in a society . After the passing of Muhammad, there was a need for jurists, to decide on new legal matters where there is no such ruling in the Quran or the Hadith, example of Islamic prophet Muhammad regarding a similar case . </P> <P> In the years proceeding Muhammad, the community in Madina continued to use the same rules . People were familiar with the practice of Muhammad and therefore continued to use the same rules . </P>

Can you explain the basic concept of fiqh