The Four Sources (Adilla Shar’iyya)
1. Al-Quran al-Karim: The primary source; its commands are binding when explicit; its general principles govern interpretation of other sources.
2. Al-Sunna al-Nabawiyya: The Prophet’s sayings, acts, and tacit approvals. Usul al-fiqh distinguishes:
- Mutawatir (mass-transmitted): binding, certain
- Mashhur (well-known): near-certain
- Khabar al-wahid (single-narrator): probably binding but not certain — school differences here are major
3. Al-Ijma’ (Scholarly Consensus): Agreement of qualified scholars on a ruling after the Prophet’s death. Theoretically irrefutable once established; practically, defining whose agreement and on what question is contested.
4. Al-Qiyas (Analogical Deduction): Extending a known ruling to a new case by identifying the shared ‘illa (effective cause). Example: wine is prohibited because it is intoxicating → anything intoxicating is prohibited.
Beyond the Four: Secondary Principles
Different schools accept additional sources:
- Istihsan (juristic preference — Hanafi): departing from strict analogy for a better outcome
- Maslaha mursala (public interest — Maliki/Hanbali): rulings based on discernible general welfare
- ‘Urf (custom): legally recognized where not conflicting with the sources
- Sadd al-dhara’i’ (blocking means to harm): prohibiting a lawful act that leads to unlawful outcomes
Ijtihad: The Gates Open or Closed?
The classical debate: after the 4th century AH, did the “gates of ijtihad close” — requiring all subsequent jurists to follow one of the four schools (taqlid)? The phrase “closing of the gates” is modern scholarly shorthand; classical scholars did not use it. In practice, qualified scholars in every century performed new ijtihad. The Ismaili tradition: the Imam is himself the living source of ijtihad — his interpretation (ta’wil) is not bound by prior scholarship.
See also: Sunna Al Nabawi, Seerah Al Shafii, Seerah Imam Malik, Seerah Abu Hanifa, Seerah Ibn Hanbal, Quran Sciences