“Geometry of the Spirit”: Sufism, Calligraphy, and Letter Mysticism
by Meena Sharify-Funk
To all Muslims, the word beyond comparison—the language that exists beyond all rules and standards and yet simultaneously creates all rules and standards—is the Qur’an, the Holy Book, the revealed message of Islam. It is the miracle, al-Mu‘ajizah, the source of all Muslim ways of knowing (whether orthodox, rational, or mystical), and it is the basis for all spiritual experience as well as the source of legitimacy for all social and moral values. Linguistically, it is the foundation of classical Arabic and the standard for eloquent literary expression.
The significance of the Qur’an as the origin and central source for the development of Sufism cannot be overstated. As manifested in Quranic concepts, principles, and practices, the Sufi way of life was and has been embedded in experiencing the Quranic revelation exemplified in the model of the Prophet Muhammad. Within 300 years after the death of the Prophet in 632 CE, Sufi Quranic hermeneutics—the art of Sufi interpretation of the Qur’an—would emerge and develop into a complex, diverse web of understandings. Sufi interpretations of the Qur’an, however, were by no means uncontested, and were a key thread in great debates about how to be Muslim as well as the nature of the Qur’an and the varieties of Quranic knowledge. These debates over appropriate methods for studying the Qur’an, and comprehending its symbolic themes and stories, came to have great significance in defining the content of Islamic practice and spirituality, and have persisted from formative times to the present.
Sufi writers played a key role in early debates over Quranic interpretation, in disagreements about what constituted “legitimate” or authoritative commentary and experience. These debates revolved around the very nature of claims that could be made about the Qur’an as a source of spiritual and moral guidance, and gave rise to schools of thoughts that have since been characterized as esoteric or exoteric. Where a more esoteric approach was upheld, the Qur’an was a source of spiritual inspiration that was profoundly personal in nature, which could not be limited by purely formal and literal expositions. Scholars who emphasized exoteric knowledge of the Qur’an sought to delegitimize subjective experiences of the text and to establish objective criteria for valid interpretations of the Qur’an’s theological and behavioral meaning.
Since the Qur’an represents the divine word or logos made first into a recitation and then into a book, Muslims have thus developed a reverence for both recitation and the written word, and traditions of beautifying them. Some of Islam’s most widespread and profound art forms directly result from this reverence, notably the art of Quranic calligraphy. Esoterically, many Sufis took the letters of the Arabic alphabet as symbols not only in a linguistic sense, but in a cosmic sense as well: some of Sufism’s most elaborate metaphysical systems have been expressed utilizing letters as cosmic symbols. In this article, we will explore the significance of Quranic calligraphy and the art of letter mysticism from a variety of Sufi perspectives.
- Quranic Calligraphy and Sufism
From the very beginning of Islam, listening to and reciting the Qur’an has been a core practice of Islamic spirituality. In listening to the sacred word and then reciting it, practitioners of Islam emulate the spiritual experience of the Prophet Muhammad receiving the Qur’an from the Angel Gabriel, and then articulating it as transformative speech. The spoken word thus lies at the very heart of Islamic spirituality and culture.
The Sufi tradition reflects this Islamic emphasis on auditory and oral experience, and the methods of spiritual practice developed by Sufis have centered around attaining realization by means of contemplation focused on divine words.
Both in Islamic religious culture more generally and in the Sufi tradition, the centrality of the divine Word led not just to perfunctory written preservation of oral revelation, but also to a flowering of artistic efforts to write the divine word in beautiful ways. For many Sufis, this practice of writing the sacred word took on added levels of significance, encouraging them to play a very active role in the development of Quranic calligraphy. As Seyyed Hossein Nasr writes, they experienced calligraphy as an attempt to communicate spiritual truths and realities:
Islamic calligraphy is the visual embodiment of the crystallization of the spiritual realities (al-haqa’iq) contained in the Islamic revelation. This calligraphy provides the external dress for the Word of God in the visible world but this art remains wedded to the world of the spirit. For according to the traditional Islamic saying, ‘Calligraphy is the geometry of the Spirit.’1
Islamic religion, culture, and civilization would not be the same without the presence of calligraphy as manifested in a variety of forms, from religious texts and poetry to architecture and objects of everyday life. Calligraphy is “the progenitor of traditional Islamic visual arts.”2
In their pursuit of calligraphy, Sufis emulated the broader norm within Islamic culture to give deep respect to the capacity of the written word to convey revealed truths. They regarded Quranic calligraphy as a holy art that offers baraka (sacred blessings) to the recipient of its beauty and wisdom. They contemplated not just the divine Quranic words and chapters (surahs) in themselves, but also the Arabic letters as constituent elements of divine speech. The practice of calligraphy thereby became integrated with other methods of Sufi practice, and included reflection on sacred and symbolic qualities of Quranic words.
Cousin and son-in-law to the Prophet Muhammad, Ali ibn Abi Talib, who was the progenitor of many Sufi orders, is credited not only as the founder for the study of rhetoric (al-balagha) and Arabic syntax (‘ilm al-nahw), but also as the developer of Kufic, the oldest style of Quranic calligraphy. Sufi legend claims that following in the tradition of Prophet Idris, who is believed to have invented a writing system with no curved lines known as ma‘qili, Ali developed the Arabic script of “Kufic.”3
Known as the “liturgic script par excellence” for early Qur’ans, Kufic consisted of a division of 1/6 curved and 5/6 straight lines. Although many different calligraphy styles would follow Ali’s Kufic, most calligraphers place much significance on their link to Ali, “the first master of calligraphy.”4 Some Sufis (e.g., Mir ‘Ali of Tabriz) even claim Ali as the principal source of inspiration for their own inventions in calligraphy.5
Ali’s dual status as the progenitor of many Sufi orders and of the art of calligraphy has reinforced natural connections between Sufi practices and the practice of writing in Arabic as a spiritual as well as artistic discipline. Just as various Sufi orders are careful to trace their spiritual lineages to Muhammad by means of Ali, Sufi calligraphers of different styles and techniques similarly honor Ali as the source of their artistic as well as spiritual pedigrees. In ways that mirror the Sufi master-disciple relationship, serious students of calligraphy are expected to study with a certified calligraphic master who ultimately has the right to bequeath an ijaza—a certificate of permission to be a khattat, or recognized calligrapher and member of a certain calligraphic school. Historically, Sufi orders provided highly conducive contexts for the study and development of calligraphy, with a variety of different orders becoming known for their own distinctive contributions to the art and its diverse formal expression. These orders included the Mevlevi, Naqshbandiyya, Qadiriyya, Khalvatiyya, and Dhahabiyya, as well as many others.
To practice calligraphy as an integral component of their spiritual practice, many Sufis found great inspiration in Quranic passages affirming the sacred nature of writing. Of particular significance were verses attributing cosmological significance to the pen (al-Qalam) and the “preserved tablet” (Lawh al-Mahfuz). References to the pen can be found in what are understood to be the first two revealed chapters (surahs) of the Qur’an—96:1-5: “He [God] taught humans by the Pen!’” and Surah 68 which begins with, “Nun [an Arabic letter], and by the Pen! And by the record which humans write. . . .” The idea of the “preserved tablet” as a spiritual reality or metaphor appears in a later Quranic chapter, 85:21-22: “Verily, this is a glorious Qur’an, inscribed on the Preserved Tablet.”
|Nuria Garcia Masip
Surah Al Qalam (The Pen), Koran 68:1
Nun, By the Pen and by that which (men) write
Nun, wa’l qalam wa ma yasturûn, 2008
Celi sülüs script
Black soot ink and gold on paper
47 x 51.5 cm.
The scriptural prevalence of ideas linked to writing provided great inspiration to Sufis and Sufi calligraphers. Quranic passages conveying the idea of a heavenly pen (al-Qalam), for example, suggest a correspondence between human practices of writing and God’s acts of teaching humanity through the creation of holy books. The idea of a divine book or tablet (al-Lawh) upon which all is recorded similarly infuses macrocosmic significance into the microcosmic practice of human writing, while evoking an ancient Middle Eastern belief that all holy and sacred books have been written on a heavenly book or tablet which also contains the mysteries of the universe as well as the secrets of human lives.
The presence of such content within the Qur’an was a source of great inspiration for Sufi cosmology as well as for the calligraphic arts.
Ibn al-‘Arabi (d. 1265), one of the foremost exponents of Sufi metaphysics, considered the Quranic pen to be a symbol of the “First Intellect” and an embodiment of the creative principle present within al-Badi‘ (“The Originator”), one of God’s “ninety-nine most beautiful names.”
By its very nature, calligraphy provided a living reminder of divine creativity and its manner of manifesting the unseen. The pen of calligraphy evoked the Primordial Pen by which all was created. Pursuit of excellence in the arts of calligraphy invited further reflection on how one’s human state of being might be brought to a state of perfection, within which a created human being might become a mirror of the divine.
Sufi reflections on these themes were extensive. One influential school of thought, based particularly on Ibn Arabi’s 13th-century synthesis of Sufi ideas, reasoned that if the “pen” mentioned in the Qur’an is Originator of everything and the Lawh al-Mahfouz (“preserved tablet”) preserves all that has been written by the Pen, then the first visual point inscribed by the cosmic pen would represent the “primordial dot.” This “primordial dot” was itself a symbol of divine Ipseity (self-identity) and the basis of creation.
Such formulations proved immensely significant for calligraphers, as they infused the craft with layers of mystical as well as exoteric meaning. For technical as well as spiritual reasons, “the science of the dot” became a central preoccupation of calligraphy.
Annemarie Schimmel alludes to this correspondence of formal precision and spiritual meaning when noting that Ibn Muqla (d. 940), a native of Shiraz, Iran, developed his influential science of dot-based proportions during the lifetime of one of early Sufism’s most controversial ecstatic figures, Mansur al-Hallaj (d. 922).6
Significantly, one of al-Hallaj’s many mystical treatises, al-Tawasin, dealt with the idea of the dot as a metaphysical reality and spiritual symbol. Shiraz, a cosmpolitan city in southern Iran, became one of the more significant places where al-Hallaj’s ideas were embraced and carried forward in the years after his execution. Shiraz’s status as a center for calligraphy, book-making, and other arts—including the production of “pens of the highest quality”—may well help to explain the warm reception al-Hallaj’s ideas received in the city during the classical period of Sufism.
Ibn Muqla developed a system of a proportioned Arabic alphabet that was based on the art of sacred geometry. For Ibn Muqla, every Arabic letter is in relation to a circle and its diameter. The point, or nuqta, was the ultimate means for precise measurement. This one was written in 2014 by Ahmed Fares, an Egyptian master calligrapher. It measures 80 cm. wide by 60 cm. tall and uses handmade Japanese ink on handmade acid-free paper. The alif is pure gold.
Both Sufis and Sufi calligraphers regarded the dot not just as the beginning of all letters, but also as a sign of God’s creative power. The dot provided a multivalent symbol that simultaneously evoked the origination of letters, the origins of the universe, and even Ali as the originator of calligraphy and as a critical source for Sufi lineages.
When referring to the dot underneath the second letter of the Arabic alphabet, ba, Sufis explained that it represented not only the beginning of words, but also the “First Intellect” manifesting from the unknown Divine Essence and even Ali himself in his extensive wisdom. As a dot in writing starts a pen’s journey, so too does the First Intellect stir life into motion and energy. Evoking this primordial creativity, Ali had helped give form and inspiration to traditions of gnosis and calligraphy.
The point below the letter ba’ ascending above the letter nun.( Made by Joseph Schaffer)
- The Sufi Art of Letter Mysticism
“We were lofty letters not yet pronounced, latent in the highest peaks of the hills. I was you in Him, and we were you and you were He and the whole is He in Him—ask those who have attained.”7
For Sufis, language is an intertwined combination of revelation and logic. Language is understood to have a divine origin. Sufis do not deny historical investigations concerning the developmental origins of signs, words, and grammars, but believe that, just as the continuous processes of creation are guided by divine purpose, so too are processes of linguistic development.
Moreover, the process of tracing the meaning of a word back to its root is, in many respects, comparable to the search for essence, and for spiritual sources of human experience.
Language, then, is a divine code, associated with the abstract principles through which the universe was created. The letters of alphabets have metaphysical significance as well as practical utility; they are sometimes even understood to be “beings,” or the equivalent of “cosmic DNA.”
The entire text of the Qur’an can be experienced as a window upon Reality through the medium of language. While meanings can be disputed or forever rediscovered in new ways, the idea that language is impregnated with inherent meaning and significance is deeply rooted. Because the Qur’an was revealed in Arabic, Sufis have sought access to spiritual experience through the medium of the Arabic language. However, other Muslim languages such as Persian, Turkish, and Urdu were also regarded as suitable vehicles for communicating mystical ideas, particularly in the form of poetry.
For the Sufi, language provides a systematic (but not necessarily “linear”) means of attaining to and expressing spiritual states of being, and is therefore concerned not only with the management of social relationships but also with divine-human communication. Deep penetration into the forms of language can reveal an underlying grammar and a generative sound code that correspond with higher, more abstract levels of reality emanating from the divine source. Such profound contemplation of language—particularly but not exclusively the language of a holy book or saints—intensifies and enriches a spiritual path, providing a point of contact with God as the source of this language, and helping to clear the way for revelatory experience of the transcendent.
The goal of Sufi contemplation is to attain Oneness with the One, beyond all ordinary ideas of “relationship.” Although all of creation attests to its origin in God, and can by analogy be understood as a collection of letters or signs created by God’s pen, this “alphabet of existence” is itself ultimately an expression of God that is (in the metaphysics of Ibn al-‘Arabi) “not other” than He. Thus, language simultaneously evokes diversity and unity:
|Letters written with ink do not really exist as letters, for the letters are but various forms to which meanings have been assigned through convention. What really and concretely exists is nothing but the ink. The existence of the letters is in truth no other than the existence of the ink, which is the sole, unique reality that unfolds itself in many forms of self-modification. One has to cultivate, first of all, the eye to see the self-same reality of ink in all letters and then to see the letters as so many intrinsic modifications of the ink.8|
Language to a Sufi is perceived in a paradigm of relevatory experience wherein “the word” is the most refined and eloquent means of exchange, whether cosmological or social. Paradoxically, language can itself suggest a means of annihilating language in pursuit of that which lies behind it, thus transcending “the word” in order to experience “the word” in all of existence. To arrive at this non-dualistic realization is “to have no relation”—and therefore to be at One, to be all and whole. Contemplation of a spiritual language such as Arabic in light of such a non-dual aspiration facilitates revelatory experience and contributes to the realization of wahdat al-wujud, the unity of being.
Hassan Massoudy, a native of Najef, Iraq, is a world-renowned master of contemporary Arabic calligraphy whose works bring light to a variety of Sufi personalities and their well-known sayings. His style of calligraphy opened new horizons in contemporary Quranic calligraphy. This calligraphic piece is a saying by Ibn al-‘Arabi from his book of poetry, Interpreter of Desires: “I believe in the religion of love, wherever its stages may go, love is my religion and faith.”
more info about Hassan Massoudy
As previously mentioned, Sufis regard the words, verses, and chapters of the Qur’an not just as written language but also as beings which guide humans back to divine unity. Even the constituent elements of language, the letters, have divine power, and the disciplines of writing have spiritual significance. From a Sufi perspective, the science of letters (‘ilm al-huruf) or letter mysticism (al-huruf al-mana‘) is the art of expressing meaning from the letters and their multiple combinations and interpreting that meaning as it connects to a higher, cosmological order. Letters, therefore, are phonetic as well as phenomenological signs that are valued not only for semantic value but also for existential/spiritual value and arithmetic value. Following in the tradition of the Prophet Muhammad, “to worship with total presence as if one is actually seeing one’s Lord in all things,” the Sufi extends this aspiration toward spiritual presence and vision into language, as reflected in the Sufi saying that “there is no letter which does not worship God in a language.”9
One of the most significant figures in the development of this Sufi view of language was Ja‘far al-Sādiq (d. 765), a renowned scholar of religious sciences and descendent of the Prophet. Al-Sādiq is also regarded as the sixth Imam in Shi‘a thought. His wide-ranging legacy has influenced a variety of movements, including alchemy, theology, mysticism, jurisprudence, and Quranic hermeneutics.10
As reflected in the following excerpt, his writings emphasize the esoteric significance of the letters and their role in the larger scheme of creation and existence:
|In the first place a thought surged in God, an intention, a will. The object of this thought, this intention, and this will were the letters from which God made the principal of all things, the indices of everything perceptible, the criteria of everything difficult. It is from these letters that everything is known.11|
According to a Quranic commentary, al-Sādiq inherited a book of esoteric teachings from Ali ibn Abi Talib, inscribed on lamb’s skin (jafr).12 His teachings on the Arabic letters are attributed to this source, hence the science of interpreting the multiple meanings of the letters and numerical values assigned to them would be called jafr. The study of jafr is thought to reveal a mathematical structure that underlies the Qur’an. For example, certain phrases are repeated in a mathematical pattern. This kind of numerological analysis has strong resemblance to the Kabbalistic practices of Jewish mysticism.
Many Sufis find support for such mystical understandings of language from Quranic teachings about how God taught Adam the names of all things (i.e., taught him about their true inner nature), and in the mysterious invocation of combinations of isolated or abbreviated letters that preface 29 of the 114 Quranic surahs. Some examples of these “mysterious letters” (muqatta‘at) are found in chapter 68, “The Pen”—the second revealed chapter to the Prophet Muhammad which starts with the letter Nun—and chapter 2 in the written Qur’an, which begins with Alif, Lam, Mim.
In Sufi understandings, the sacred character of each letter is symbolized in both its form and in its meaning: “Each letter has a ‘personality’ of its own and symbolizes in its visual form a divine quality since the letters of the sacred alphabet correspond to features and qualities of God as the Divine Scribe.”13
Alif, being the first letter of the Arabic alphabet, is “the letter par excellence” from which all letters are derived. Its vertical, linear form is a perfect symbol of the unifying Principle of “as above, so below,” wherein the heavens and the earth are ultimately one. Sahl at-Tustari (d. 896) states, “Alif points to God who is the alif the one who has connected all things and yet is isolated from all things.”14 For many Sufis, alif provides a powerful metaphor for the purified state toward which the spiritual seeker aspires to return. A desire to become the alif of Allah is often found in mystical poetry, as in the statement by Shamsuddin Hafez (d. 1389), “There is no trace upon the tablet of my heart save the alif of stature of the Friend. What can I do, my master taught me no other letter.”15
The following is a story about Bullah Shah (d. 1757), a Sufi poet and philosopher from the Punjab, whose poetry is put to song by renowned contemporary Sufi performers such as Abida Pareveen and Nazrat Fateh Ali Khan. It is an excerpt from the contemporary Sufi Hazrat Inayat Khan’s The Inner Life, which is the first volume of his collected writings.
|In the life of Bullah Shah, the great Sufi saint of Punjab, one reads a most instructive account of his early training when he was sent to school with boys of his own age. The other boys in his class finished the whole alphabet while he was mastering the same letter. When weeks had passed, and the teacher saw the child did not advance any further than the first letter Alif, he thought that he must be deficient and sent him home to his parents, saying, ‘Your boy is deficient, I cannot teach him.’
The parents did all in their power for him, placing him under the tuition of various teachers, but he made no progress. They were disappointed, and the boy in the end escaped from home, so that he should no longer be a burden to his own people. He then lived in the forest and saw the manifestation of Alif which has taken form in the forest as the grass, the leaf, the tree, branch, fruit, and flower; and the same Alif was manifested in the mountain and hill, the stones and rocks; and he witnessed the same as a germ, insect, bird and beast, and the same Alif in himself and others. He thought of one, saw one, felt one, realized one, and none else besides.
After mastering this lesson thoroughly he returned to pay his respects to his old teacher who had expelled him from school. The teacher, absorbed in the vision of variety, had long ago forgotten him; but Bullah Shah could not forget his old teacher who had taught him his first and most inspiring lesson which had occupied almost all his life. He bowed most humbly before the teacher and said, ‘I have prepared the lesson you so kindly taught me; will you teach my anything more that may be to learn?’ The teacher laughed at him and thought to himself, ‘After all this time this simpleton has remembered me.’ Bullah Shah asked permission to write the lesson, and the teacher replied in jest, ‘Write on this wall.’ He then made the sign of Alif on the wall, and it divided into two parts. The teacher was astounded at this wonderful miracle and said, ‘Thou art my teacher! That which thou hast learnt in the one letter Alif, I have not been able to master with all my learning,’ and Bullah Shah sang this song:
This story speaks both to spiritual significance Sufis have ascribed to letters, and to the special status of alif as the character which begins the Arabic alphabet and the word, “Allah.” Sufis have regarded alif as the foremost and most elemental of the letters, even depicting it as the letter from which others have been derived. Similar to the biblical and Quranic story of Adam made in the likeness of God, so too are the letters made in the image of the alif. Al-Muhasibi (d. 857), a leading theologian and psychologist with strong Sufi influences, used dialectical reasoning to debate the Mutazilites, a school of rationalist theologians, and communicated this understanding with a story: “When God created the letters he ordered them to obey. All letters were in the shape of alif, but only the alif kept its form according to the image in which it was created.”17
If all letters come from the alif, as this story depicts, why learn the others? Although alif possesses a special status, Sufis have attributed spiritual meaning and significance to each of the other letters of the Arabic alphabet. Each letter is understood to have inherent qualities that are manifestations of divine attributes and names. Taken together, the alphabet has provided Sufis with a way of thinking about an underlying “software” of creation through which God continually creates and recreates the universe. This understanding is present in the words of Titus Burckhardt as he describes “two dimensions” of calligraphy:
|The richness of the Arabic script comes from the fact that it has fully developed its two ‘dimensions’: the vertical, which confers on the letters their hieratic dignity, and the horizontal, which links them together in a continuous flow. As in the symbolism of weaving, the vertical lines, analogous to the ‘warp’ of the fabric, correspond to the permanent essences of things—it is by the vertical that the unalterable character of each letter is affirmed—whereas the horizontal, analogous to the ‘weft,’ expresses becoming or the matter that links one thing to another.18|
Ibn al-’Arabi’s Cosmology of the Letters. A comological chart created by Titus Burckhardt to describe Ibn al-’Arabi’s mystical interpretation of the Arabic letters as corresponding to Quranic names of the Divine. Each letter represents a particular attribute and cosmic reality. From Laleh Bakhtiar’s Sufi: Expressions of the Mystic Quest (New York: Thames & Hudson, 1976), 62. Image used with permission.
Note: here the book of Titus Burckhardt about Ibn al-’Arabi’s mystical interpretation of the Arabic letters
Far from regarding the letters as arbitrary building blocks of human language, Sufis have perceived cosmic significance in an alphabet that provides a medium for weaving the very tapestry of existence, and that manifests itself in divine as well as human speech.
Beauty in Islam comes in many artistic manifestations and Quranic calligraphy has presented exquisite forms of harmony and majesty. Many Sufi personalities embraced calligraphy as a sacred practice, and as a vehicle for reflection on divine mysteries. In a spiritual tradition that revolves around the revealed word of God, calligraphy provided an additional means of contemplation, in addition to memorization of Quranic passages and oral recitation. For many, cultivating mastery of Quranic calligraphic expressions became a method of Islamic spirituality that opened hidden dimensions of the universe. This spiritual art would connect the seeker and practitioner not just to scripture, but also to past legendary masters. Training in calligraphy linked the student to a spiritual heritage that included esoteric discipline and doctrine.
The practice of calligraphy invited practitioners to focus on the symbolism of the Quranic words and letters, a preoccupation with essential meanings of the constituent elements of revealed scripture. This emphasis on seeking the essence of religious forms resonated deeply with Sufi thought, and provided Sufis with an additional means of understanding divine unity in its diverse manifested modalities. For Sufis, contemplating the forms and meanings of Arabic letters enabled perception of deeper cosmological and metaphysical truths. The letters themselves were regarded as theophanic forms offering clues for encountering God and returning to the purified, primordial nature of the human being. Thus, the practice of calligraphy could become an existential journey, a basis for looking deep into a divine mirror to rediscover the core of one’s being in a transcendent context. The mastery of letters provided the ABC template (or, in Arabic terms, the alif-ba) for deciphering God’s mysteries.
- S. H. Nasr, Islamic Art and Spirituality (Albany: SUNY Press, 1987), 18.
- Ibid., 19.
- A. Schimmel, Calligraphy and Islamic Culture (New York: New York University Press, 1984), 3.
- Ibid., 47.
- Ibid., 18.
- Ibn al-‘Arabi, in Schimmel, 89.
- Persian mystic, Haydar-i Amuli, in T. Izutzu, “The Basic Structure of Metaphysical Thinking in Islam,” in Mehdi Mohaghegh and Hermann Landolt, eds., Collected Papers on Islamic Philosophy and Mysticism (Tehran: Iranian Institute of McGill University and Tehran University, 1971), 66.
- Schimmel, Calligraphy, 81.
- M. Sells, Early Islamic Mysticism: Sufi, Qur’an, Mir’aj, Poetic, and Theological Writings (Mahwah: Paulist Press, 1996), 151.
- A. Schimmel, Deciphering the Signs of God: A Phenomenological Approach to Islam (Albany: SUNY Press, 1994), 151.
- F. Mayer, trans., Spiritual Gems: The Mystical Qur’an Commentary Ascribed to Jaf‘ar al-Sādiq as Contained in Sulami’s Haqa’iq al-Tafsir from the Text of Paul Nwyia (Louisville: Fons Vitae Publishers, 2011), 4.
- Nasr, 30.
- Sahl at-Tustari in Schimmel, Calligraphy, 94.
- Nasr, 31.
- Inayat Khan, The Sufi Message of Hazrat Inayat Khan: The Inner Life (Geneva: International Headquarters of the Sufi Movement, 1979), 40-41.
- al-Muhasibi in Schimmel, Calligraphy, 94.
- Titus Burckhardt, Sacred Art in East and West (Louisville: Fons Vitae Publishers, 1967), 159.