In addition to the Koran, early jurisprudence relied on Sunna, which seems to have originally meant the general or time-honoured usage of the community and ra'y, which at this stage meant "sound opinion" or "considered opinion." With the work of al-Shfi'i, and generally for Sunnis in the course of the ninth century, it became standard theory that there was not one scripture in Islam, but actually two. The definition of Sunna narrowed to refer ...
