Sufis, Ismailis, and Alevis affirm that revelation carries an inner, hidden meaning (batin) beneath its outward, literal sense (zahir), and that grasping the inner is the deeper aim of religion. On this view the Quran addresses the ordinary believer through its plain sense and the spiritually advanced through layers of allegory and symbol, so that a verse about ritual or narrative also speaks of the soul's ascent or cosmic realities. The tradition holds that access to the inner meaning comes through spiritual insight, and in Ismaili thought specifically through the guidance of the Imam.
The distinction has an old textual pedigree within Shia and esoteric Islamic thought: a hadith attributed to the sixth Imam, Jafar al-Sadiq, describes the Quran as possessing an outer expression, an inner meaning, a limit, and a point of ascent, and some versions of similar traditions speak of as many as seven layers of meaning beneath the literal text. The tenth-century Ikhwan al-Safa, the Brethren of Purity, an anonymous encyclopedist circle whose epistles blended Islamic and Greek philosophical themes, developed a systematic esoteric hermeneutic along similar lines, and their work influenced later Ismaili philosophical tradition even though the Brethren's own sectarian affiliation remains debated among scholars.