Following are the different stages through which Shi'ah Muslim Fiqh (jurisprudence) passed.

1. The first stage commenced from the time of the Holy Prophet (s.a) and extended to the era of al-Sadiqayn (Imam Muhammad al-Baqir and Imam Ja'far al-Sadiq (a.s)). In fact, the origin of Shi'ah Muslim Fiqh is traceable to the following Hadith from the Holy Prophet (s.a):

"As long as Ali (a.s) is in the mosque, no one besides his has permission to pronounce any Islamic decree. 37"

In the works on Islamic issues such as 'a'yan al-Shi'ah, al-Muraja'at, T'asis al-Shi'ah and Jami'a, the answers from Fiqh to legal cases are ascribed to Imam Ali (a.s) 38.

2 There are also certain Sunni authors who have collected the pronouncements of Imam Ali (a.s) in Fiqh 39. The author of Mawsu'ah Fiqh Ali Ibn Abi Talib states that Ali used to pronounce rules of the Islamic law even in the time of the Prophet (s.a) and the Prophet would subscribe to such pronouncements. Accordingly, Sahabah (companions) would take into account Imam Ali's views in all matters. The Caliphs acknowledged: " The holy Prophet had ordered us to consult Ali in the matters of law. " Sahabah never ventured beyond his pronouncements of Islamic rules. In this regard Ibn Abbas has said:

"Whenever Ali made his pronouncements (in the matters of the Islamic rules) we would follow no other pronouncements. 40"