Key Content and Themes

The Quran as a source of law receives careful treatment in the Al-Wajiz. Az-Zuhayli covers the principles for extracting legal rulings from Qur'anic text: the theory of commands (amr) and prohibitions (nahy) and their implications for obligation and prohibition; the classification of Qur'anic language as clear (muhkam), ambiguous (mutashabih), general ('amm), specific (khass), absolute (mutlaq), and restricted (muqayyad); and the principles for resolving apparent contradictions through abrogation (naskh) or specification (takhsis). Each of these technical categories is explained with examples drawn from actual Qur'anic verses and the legal rulings derived from them.

The treatment of the Sunnah addresses the foundational questions of prophetic authority: why the Prophet's statements and actions constitute binding guidance, how the different categories of Sunnah (verbal, practical, tacit) relate to each other and to the Quran, and how the hadith sciences ensure that authentic prophetic traditions are distinguished from fabrications. Az-Zuhayli also addresses the theory of mutawatir (mass-transmitted) versus ahad (single-chain) traditions and the different schools' views on the legal weight of ahad hadith.

The sections on ijma' (consensus) engage with one of the most theoretically contested topics in Islamic legal theory. Az-Zuhayli explains what consensus means, whose agreement counts as consensus, how consensus is established, and what its binding force is. He carefully distinguishes the different schools' positions on these questions without flattening them into false agreement.

The treatment of qiyas (analogical reasoning) is central to the work. Az-Zuhayli explains the four elements of legal analogy — the original case, the new case, the common element, and the legal ruling — and works through the methodology for identifying and validating the common element (illah, or effective cause). He covers the conditions for valid analogy and the types of analogy recognized by different schools.

The secondary sources receive balanced treatment. Istihsan (juristic preference), a methodology associated particularly with the Hanafi school, is explained on its own terms with the Hanafi justifications for its use, alongside the criticisms advanced by Al-Shafi'i and others. Similarly, maslaha mursalah (public interest reasoning), associated with the Maliki tradition, is presented with its theoretical basis and scope.

A persistent theme throughout is the relationship between the formal machinery of legal theory and the underlying goal of serving human welfare while honoring divine command. Az-Zuhayli repeatedly connects theoretical principles to their practical implications and to the higher objectives (maqasid) of Islamic law.