The Quran in Islamic Legal Theory

Abu Zahrah's treatment of the Quran in legal theory goes beyond affirming its authority to analyzing the precise ways in which its linguistic character determines how it functions as a source of law. This analytical approach, grounded in the science of Arabic linguistics applied to the Quranic text, is one of the most distinctive features of classical usul al-fiqh and distinguishes it from simple citation of Quranic verses in support of legal positions.

The fundamental distinction in Quranic interpretation for legal purposes is between the qat'i (definitive) and the dhanni (speculative or probable). A qat'i text is one that can bear only one meaning — its linguistic form is so clear and unambiguous that no reasonable alternative interpretation is possible. A dhanni text is one that, while pointing to a specific meaning, can also bear alternative interpretations that reasonable scholars might embrace. The practical consequence of this distinction is significant: rulings derived from qat'i texts are themselves qat'i — they are established with certainty and cannot legitimately be departed from. Rulings derived from dhanni texts are themselves dhanni — they are probable and may be challenged by scholars through careful reasoning.

Abu Zahrah examines several categories of Quranic language relevant to legal derivation. The 'amm (general) text applies to all instances of a category without exception, unless a specific exception (takhsis) is indicated. The khass (specific) text applies only to the particular case it addresses. The mutlaq (unconditional) text applies without restriction, while the muqayyad (conditional) text is qualified by conditions. The mujmal (ambiguous) text requires explanatory hadith to clarify its meaning. Each of these categories has specific rules governing how it is to be understood and applied.

The principle of abrogation (naskh) is also addressed by Abu Zahrah as a critical element of Quranic legal interpretation. Some Quranic rulings were superseded by later revelations during the prophetic era — the direction of prayer was changed from Jerusalem to Makkah, certain previously permitted practices were subsequently prohibited, and some rulings were modified over time. Understanding which texts are abrogating (nasikh) and which were abrogated (mansukh) is essential for applying Quranic law correctly. Classical scholars devoted extensive effort to identifying and documenting these instances of abrogation.

Abu Zahrah also addresses the principle of the 'objectives of Islamic law' (maqasid ash-Shariah) as a tool for Quranic interpretation. The classical formulation by al-Ghazali and subsequent scholars identified five essential objectives that the Quran's legal provisions are designed to protect: life (nafs), intellect ('aql), lineage (nasl), property (mal), and religion (din). When interpreting Quranic texts, particularly in situations of ambiguity or apparent conflict, the jurist considers which interpretation better serves these five objectives. This teleological dimension of Quranic interpretation prevents a purely literalistic approach from producing outcomes contrary to the law's evident purposes.