After it became accepted that legal norms must be formally grounded in scriptural sources, proponents of rules of jurisprudence supported by the hadith would extend the chains of transmission of the hadith back to Muhammad's companions. In his view, the real architect of Islamic jurisprudence was Al-Shafi‘i (d. 820 CE/204 AH), who formulated this idea (that legal norms must be formally grounded in scriptural sources) and other elements of classical legal theory in his work "al-risala", but who was preceded by a body of Islamic law not based on primacy of Muhammad's hadiths.