An esoteric interpretation of the Qur'an is an interpretation of the Qur’an which includes attribution of esoteric or mystic meanings to the text by the interpreter. In this respect, its method is different from the conventional exegesis of the Qur’an, called tafsir. Esoteric interpretations do not usually contradict the conventional (in this context called exoteric) interpretations; instead, they discuss the inner levels of meaning of the Qur'an. A hadith from Prophet Muhammad which states that the Qur’an has an inner meaning, and that this inner meaning conceals a yet deeper inner meaning, and so on (up to seven levels of meaning), has sometimes been used in support of this view.
Esoteric interpretations are found in Sufism and in the sayings (hadiths) of both Twelver and Ismaili Shi'a Imams. In Arabic, batin refers to the inner or esoteric meaning of a sacred text, and zahir to the apparent or exoteric meaning.
1.1 Islamic legitimacy
There is almost no dispute among Muslims that the Qur’an has concealed meanings. The existence of the Qur'anic initial letters is often mentioned in connection with this belief. The authority of the person who extracts these meanings is a matter of debate.
Naturally, Muhammad is considered to be the authority on interpretation of the Qur'an in any form, but his interpretations, even when discussing esoteric matters, are actually standard definitions of Qur'anic concepts due to his position as prophet of Islam.
There is a verse in Qur'an related to esoteric interpretations:
He it is who has sent down to thee the Book: In it are verses basic (of established meaning); they are the foundation of the Book: others are allegorical. But those in whose hearts is perversity follow the part thereof that is allegorical, seeking discord, and searching for its hidden meanings, but no one knows its hidden meanings except God. And those who are firmly grounded in knowledge say: "We believe in the Book; the whole of it is from our Lord:" and none will grasp the Message except men of understanding.(Sura 3:7)
In the verse quoted above, there is a stop between …except God and And those who.. and reading this way the verse attributes the knowledge of the Qur'an's hidden meanings to God alone. By removing the stop it becomes:" ...no one knows its hidden meaning except God and those who are firmly grounded in knowledge, they say…" which suggests that those firmly grounded in knowledge can extract these hidden meanings.
Both forms are valid in the Arabic language; Sunni Muslims usually read the verse with the stop, while Shi'a Muslims usually read it without the stop, and consider their Imams, who, according to Shi'a belief, are the heirs of Muhammad's knowledge, to be authorized to explain these hidden meanings.
A Sunni view
A Shi'a view
In Sufi tradition, it is believed that the esoteric meanings of the Qur'an can be extracted through mystic experiences, and as such, esoteric interpretations presented by Sufi Shaykhs are considered authentic. Today, the majority of Muslims (except Salafis) respect Sufi interpretations at least as an alternative view of the Qur'an.
Throughout its history, Sufism has widely used esoteric interpretation of the Qur'an. The metaphysical basis of a Sufi interpretation is Kashf (unveiling) or Zawq (tasting). Sufi writings make frequent references to the Qur'an and present esoteric interpretations either explicitly or implicitly. Implicit forms being quoting a verse in a certain context which suggests that the meaning of the verse is related to the ideas presented.
There are some verses in the Qur'an whose conventional interpretations suggest mystic ideas and Sufis have commented extensively on them. While all Sufi interpretations are basicallymystic, three major trends in Sufi interpretations can be recognized, mystic, philosophic, and esoteric.
The distinction is not always clear and sometimes these coexist in works of a particular Sufi author. Historically the mystic interpretations were the first to appear in Sufi writings, the second and third being philosophic and esoteric interpretations.
A famous Sufi commentary on the Qur'an, the Persian book Kashf Al Asrar (The Unveiling of the Mysteries) by Meybodi, mentions conventional interpretations as the first level of meaning and esoteric interpretations as a deeper level. It is common in Sufi writings to explain three or four levels of meaning of a Qur'anic concept.
1.2.1 Mystic interpretations
These are purely mystical interpretations of the text and at times have a poetic nature which presents mystic insights to the meaning of the Qur'an.
Some examples include:
Interpreting religious terms as describing inner qualities:
These interpretations are sometimes mystic comments on religious concepts. For example in " Say: O unbelievers! I worship not that which you worship"(109/1-2) unbelievers is taken to mean individual self, or the women of paradise, houri, are interpreted as divine visions.
Interpreting Qur'anic stories from a mystic perspective:
These interpretations are aimed at explanation of the mystic meaning of the stories and are found frequently in Sufi poems and prose, for example in The Conference of the Birds, Attar, in reference to the Qur'anic story of descent of Adam and Eve to Earth, writes that "Adam was too lofty to be satisfied with paradise and an unseen messenger cried to him to leave his attachments to everything that hampers his journey towards God, be it paradise".
These interpretations view Qur'an from a poetic perspective and seek to find subtle meanings related to divine love in the verses , an example which is found frequently in Sufi writings, specially poems, being the interpretation of "By the glorious morning light, And by the night when it is still" (93/1-2) as God's reference to the face and hair of Mohammad.
Interpreting a verse in a sense very different from its conventional meaning:
For example in his book Tamheedat, Ayn-al-Qudat Hamadani interprets "The fire of God kindled ablaze, which doth mount to the hearts"(104/6-7) which conventionally refers to the punishment in hell , as passion of divine love and interprets "the day Earth becomes that which is not Earth" which conventionally describes the day of judgment as a description of the moment of spiritual awakening or enlightenment.
Comments on Qur'anic initial letters:
Sometimes only a vague comment and sometimes a comment on each letter is given. Although Sufis insist that these initial letters conceal mysteries that can not be fully expressed in words and should be understood by means of mystic experiences.
Mystic remarks concerning Qur'anic verses like the famous saying "I am the dot (Arabic alphabet: ب) (English: B) of Bismillah" attributed to various Sufis including Shibli. Many Sufis have commented on it as description of a form of union with the divine essence.
1.2.2 Philosophic interpretations
These interpretations have a philosophical structure and sometimes serve as the basis of a mystic philosophy.
Hallaj was one of the early Sufis who presented such interpretations .For example he deeply speculated on Qur'anic idea of creation by the word Be! , which appears frequently in Qur'an e.g. : "...When He determines a matter, says to it, "Be", and it is."(19/35)
The most influential works in this area are those of Ibn Arabi.Each chapter of his book Fusus al-Hikam (The Bezels of Wisdom)  , is dedicated to a prophet mentioned in Qur’anwhich he attributes to a particular word (logos) or divine manifestation that is the subject of the chapter. Throughout the book (and all his works indeed) he proposes thoughtful and courageous esoteric interpretations of Qur'anic verses. He also wrote two commentaries of the Qur'an.
Many similar Sufi interpretations are inspired by Ibn Arabi' works, specially works of Akbari school.
1.2.3 Other esoteric interpretations
These are bodies of esoteric knowledge associated with Qur'anic concepts which have practical importance for some Sufis, a famous example is the theories concerning the six subtlitiesor lataif-e-sitta.