The Sources of Islamic Law — Quran and Sunnah

The second major division of al-Muwafaqat is the 'Kitab al-Adillah' (Book of the Evidences), which provides al-Shatibi's comprehensive treatment of the sources of Islamic law and the methodology of deriving rulings from them. His approach builds on the established usul al-fiqh (foundations of jurisprudence) tradition while adding distinctive contributions shaped by his Maqasid perspective.

The Quran is the primary source of Islamic law — the speech of Allah, eternal and uncreated, containing guidance for every domain of human life. Al-Shatibi's discussion of the Quran as a legal source emphasizes several important points. First, that the Quran must be understood in its entirety — individual verses cannot be interpreted in isolation from the rest of the text, from the Sunnah that explains it, or from the context of Islamic legislative history. This holistic reading is one of al-Shatibi's methodological signatures: the 'kulliyyat' (universals) of the Shariah are derived by induction from the totality of the textual evidence, not from isolated proof-texts.

Second, al-Shatibi emphasizes that the Quran was revealed in the Arabic language of the Arabs of the seventh century CE, and its proper understanding requires command of that language and its conventions. He argues strenuously against interpretations of the Quran that depart from the established Arabic linguistic conventions in favor of esoteric, mystical, or rationalist readings. The meaning of a text is determined by the conventions of the language in which it was expressed, and the Quran's meaning is determined by the conventions of classical Arabic.

The Sunnah — the authenticated words, actions, and tacit approvals of the Prophet ﷺ — is the second foundational source, inseparable from the Quran in function. Al-Shatibi argues against the notion, advanced by some rationalists, that the Sunnah can be subordinated to rational judgment when the two appear to conflict. The Sunnah is revelation (wahy) — 'And he does not speak from desire; it is only revelation revealed' (Quran 53:3-4) — and like the Quran, it takes precedence over rational inference in all matters where clear textual guidance exists.

Al-Shatibi's important contribution regarding the Sunnah is his distinction between the various types of prophetic acts and statements and the appropriate level of legal obligation each generates. The Prophet ﷺ acted in several capacities: as conveyor of divine revelation (tabligh), as the exemplary Muslim worshipper (imamah), as a judge (qada'), as a political and military leader (imarah), and as a private individual (tabi'iyyah bashariyyah). Not all of his acts carry the same level of legislative force: his private acts as a human being — his personal preferences in food, his particular habits of dress — are not necessarily obligatory for the Muslim community, though emulating them is recommended out of love. His acts in the capacity of conveying revelation are obligatory. This nuanced analysis of prophetic precedent helps scholars navigate the vast body of Sunnah with principled discrimination.