The first instance of an independent Sufi institution was the establishment of a Sufi duwayrah (small house or convent) by some followers of an early Sufi master Abd al-Wahid b. Zayd (d. 150 AH/ 767 CE). Abd al-Wahid b. Zayd lived in Basrah where for sometime he accompanied and studied with al-Hasan al-Basri (d. 110 AH/ 728 CE). During Abd al-Wahid b. Zayd’s time, Basrah enjoyed a reputation as a place where people spoke exaggeratedly about such Sufism oriented concepts as asceticism, worship, love for and fear of God, etc. Basrah is thus regarded as the birthplace of Sufism. Abd al-Wahid b. Zayd himself was known for tenacity in worship and asceticism. He was a great preacher who used to preach in mosques. He traveled a lot and often participated in holy wars (jihad). He narrated that al-Hasan al-Basri had said that every road has a shortcut, and the shortcut on the road leading to Paradise (jannah) is holy war (jihad). This and some other similar Sufi duwayrahs or little houses or convents were the antecedents of true Sufi institutions which started to emerge perhaps less than a century later. They in all probability functioned as unpretentious multi-purpose gathering places and shelters for some Sufis and their followers and novices. They also functioned as shelters and hostels for an emerging phenomenon of traveling and visiting Sufis. Some such lodges or cloisters are reported to have been built next to mosques.
Rabi’ah al-‘Adawiyyah who died in 135 or 185 AH/ 752 or 801 CE is also said to have her own hermitage where in solitude and peace she used to serve God. Apart from her hermitage, she would also make use of her house and the vastness of the desert for the purpose. People used to visit her both in her house and her hermitage. One of those alleged to have done so was al-Hasan al-Basri who grew up to become one of the most prominent figures of the second generation of Muslims (tabi’un). He was famous for his uncompromising piety and outspoken condemnation of worldliness in high places. In Sufi hagiography, he is revered as one of the greatest saints of early Islam. Another saintly figure of approximately the same era, who is described to have had a private hermitage too, and in which al-Hasan al-Basri, one of his teachers, visited him too, was Habib al-‘Ajami.
Prior to the existence of some of those little houses, convents and private hermitages in the 2nd AH/ 9th CE and the beginning of the 3rd AH/ 9th CE centuries, it is impossible to trace anything else in relation to the existence of independent Sufi institutions. This is expected because there was no Sufism before then as a recognizable and collective movement and as a specialized genre of Islamic spirituality and worship. In the context of discussing the phenomena of khanqahs and other Sufi institutions, al-Maqrizi reported that it was as early as during the caliphate of Uthman b. Affan (d. 36 AH /656 CE), the third orthodox caliph, that Zayd b. Sawhan b. Sabrah built the first houses of worship, besides mosques. He did so for a group of destitute and, most likely, homeless men in Basrah who dedicated all their times and energies to spiritual work. Since they had neither businesses nor incomes, they needed help. Consequently, Zayd b. Sawhan b. Sabrah built houses for them, designating who will be in charge of looking after them and their various needs, such as food, drink, clothing, and the like. Caliph Uthman b. Affan’s governor in Basrah, Abdullah b. Amir (d. 59 AH/ 678 CE), heard about them and is said to have attempted to lure them and to have closer and more amiable relations with them, but his overtures were snubbed at the initiative of Zayd b. Sawhan b. Sabrah. He argued that those were the men who gave themselves up to devotion and seeking God’s pleasure and His Paradise, whereas the governor’s concerns were completely different. It was feared that the spiritual men’s purity could become contaminated by the governor’s and his circles’ less spiritual and less pure aspects and features. So, the men were advised to stay put and carry on their spiritual works in their “spiritual” shelters. As a small digression, Zayd b. Sawhan b. Sabrah himself was known as a devout and steadfast ascetic. Once a companion of the Prophet (pbuh) Salman al-Farisi warned him not to overexert himself in his ascetic and devotional routines. He was reminded that his wife enjoyed her rights over him, and so did his body, so he had to respect everyone’s rights over him. However, this in no way should be conceived as a precursor for subsequent Sufi institutions. Firstly, there was never anybody called a Sufi, nor any activity, nor set of activities, called Sufism, at that time. Inasmuch as there existed neither Sufism nor the Sufis then, even in their embryonic phase, there could not be any talk of nascent Sufi institutions either. Secondly, the main objective for instituting those houses for those needy but bent on excessive devotion and asceticism men, was providing just shelters for them and taking care of their basic needs. Anything that those shelters or houses might have later been turned into, such as the places of spiritual exercises and works, was complementary or auxiliary to the primary functions of the structures which revolved around housing or sheltering those righteous men. There was nothing particularly unusual in the whole exercise. The men went, somewhat excessively though, after their spiritual business and obsessions, while someone who could afford and was aware of his social responsibilities felt that the men were doing the right thing and thus needed support. On the whole, considering the nature of the Muslim society at that point in time, that is, the time of the Prophet’s companions and their adherents, what happened then in Basrah was not way beyond a standard procedure. It was not an anomaly. And of course, knowing who those men were, it was natural that their houses or shelters were transformed into places of excessive worship and devotion, just as it is always the case with every true believer’s dwelling. Hence, the places in question were essentially private dwellings, and the essence of whatever was transpiring inside them was not different from the essence of what was transpiring outside them, just as the essence of the characters of those men was not different from the essence of the characters of other believers.
The solution for the destitute and homeless men in Basrah was somewhat similar to the solution for the most destitute people in early Madinah society during the Prophet’s time. The latter case neither can be regarded as a precursor for the subsequent emergence of Sufism and its independent institutions. It is a very well known fact that the Prophet’s mosque in Madinah since its inception served as a community development center. Among others, it served as a welfare and charity center. There, the poorest companions of the community resided. A shaded structure called suffah (a raised platform or bench) was erected for them in a corner of the northern side of the mosque. Those people were called ahl al-suffah or the “People of the suffah”. Most of the suffah dwellers were from Makkah, but some were from Madinah too. Many of them resided there not because they wanted to do so, but because they were forced by their and occasionally society’s unfavorable living conditions. Those men and their ascetic lifestyles could not be regarded as the forerunners of Sufism, nor their dwelling place and style as a precursor for Sufi institutions. It was Shihab al-Din Umar al-Suhrawardi who more than anybody else hinted at that possibility but refrained from explicitly saying so. He entitled a section of his book “‘Awarif al-Ma’arif” as “Similarities between the Residents of Ribats (Sufi Institutions) and the Residents of the Suffah”. In that particular section, the author drew parallels between the two groups of people with reference to their austere living, unremitting spiritual works, and mutual love, respect and cooperation.
The suffah “hostel” in the Prophet’s mosque could house between seventy and one hundred individuals and the number of tenants was subjected to how fast their overall condition was improving. The suffah dwellers were never idle. They spent most of their time praying, remembering Allah, reading, memorizing and contemplating the Qur’an, meditating, discussing, studying, and so forth. A man from them was chosen to be their spokesman and head, and he was directly answerable to the Prophet (pbuh) for what was transpiring in the suffah. A companion Ubadah b. al-Samit was entrusted with teaching them, apart from the Holy Qur’an, writing and reading as well.
The “People of the suffah” would frequently go out to perform whatever work they could find in order to procure their sustenance. They actively participated in jihad and some of them died as martyrs on different battlefields. Notwithstanding their difficult state, they abhorred remaining a liability to the community. By virtue of the Prophet (pbuh) having dwelled close at hand — on the eastern side of the mosque – the “People of the suffah” were actually honored to spend more time with him, and hence learn from him more than a good number of other companions. The Prophet (pbuh) would often eat with them sharing with them whatever he and his household could afford. Some of the most prominent individuals who transmitted a great deal of the Prophet’s sayings and traditions, such as Abu Hurayra and Hudhayfah b. al-Yaman, were from the ranks of the “People of the suffah”. There were actually two suffahs: one for men and the other for women, the former seemingly outnumbering the latter. It may be due to the number of its tenants and its corresponding status and position in the mosque proper, that the suffah for women was always less known and less frequently referred to.
Although the “People of the suffah” tried really hard to live on their own, they found it impossible to make ends meet. So the community had to help them in the short term by providing necessities for them almost on a daily basis (inviting the suffah dwellers for a meal or bringing food into the mosque and eating in a group was a normal occurrence), and in the long term by providing some permanent work opportunities for them, thus allowing them to stand on their own two feet as soon possible. The number of the suffah’s occupants was therefore always fluctuating. There were always those who were leaving it and those who were coming in. Seldom, however, were the exchanges in a commensurate mode, resulting thus in the place to be sometimes overcrowded and at other times to be almost vacant.
The Prophet (pbuh) never neglected the suffah and its occupants, and they were always on his mind. Whenever he received charity (sadaqah), he would send it to them without taking any of it for himself, and whenever he received a gift, he would send for them and share it with them. He often used to invite them to a meal in his house. When al-Hasan, the Prophet’s grandchild, was born, he asked his daughter Fatimah to give the weight of the baby’s hair in silver to the suffah dwellers as charity.
After duwayrahs — and perhaps somewhat concurrently with their existence – one can hear about ribats as another Sufi institution. Ribats were Sufi hospices which functioned as Sufi worship and erudition centers. In them, both the regional and traveling Sufis used to be temporarily lodged, as per their needs and the activities inside the structures. In addition, ribat cells were also used to house Muslim du’at or propagators of Islam. Originally, ribats might have been a certain type of Arabic military fortified structure because in the Arabic language the words ribat and murabatah signify battles against the enemy as well as manning Muslim outposts to protect them from enemy incursions inside Muslim territories. The Qur’an urges the Muslims to “…endure and surpass your enemies in endurance, and guard the frontiers of the Islamic nation (rabitu; ribat); and keep fearing Allah, hoping that you may succeed.” (Alu Imran, 200). The Prophet (pbuh) also said that a day of ribat in the cause of Allah is better than this life and all that is in it. The Prophet (pbuh) also said: “Should I tell you about actions with which Allah forgives sins and raises the grade: performing perfect ablution in unfavorable conditions, the many steps one takes to mosques, and awaiting prayer after the prayer, for this is the ribat, this is the ribat, this is the ribat.”
Ribat thus implies one’s constant struggle for one’s self-purification and spiritual fulfillment. It also implies patiently and steadfastly confronting one’s enemies, both physical and spiritual, and both inner and outer. The Sufis might have used the word ribat as a name for one of their nascent institutions so as to put forward the quintessence of their cause as well as the pure nature and extent of their struggle against all types of evil and its incarnates. Ribats were places of spiritual jihad or holy war. Moreover, the Sufis’ utilization of ribats as existing military fortified structures might have been two-fold: to actively participate in on-going military expeditions, and to use, and perhaps prolong as long as possible, their stay in those structures for practicing and preaching their Sufi tenets. Equally plausible is a proposition that there at first may have existed some abandoned ribats which the Sufis reconditioned and then turned into their own institutions while retaining the structures’ original name. Our inferences are based on some established truths according to which many Sufis throughout Muslim history actively participated in numerous military expeditions. It is a Sufi underlying precept that jihad (holy war) is of two types: the external one waged against the infidels, and the internal one waged against one’s base soul and Satan, the latter being greater. Each form of jihad involves its spoils of war. The external jihad entails its corresponding material and thus inconsequential spoils of war, whereas the spiritual jihad involves spiritual and thus much more coveted spoils of war.
Indeed, the two notions: jihad, both physical and spiritual, and Sufism cannot be separated. This became palpable as early as during the embryonic stages of Sufism and the various aspects of such a synthesis could easily be found in the lives of many members of the Sufi vanguard. For instance, Ibrahim b. Adham, having settled in Syria, on the border with Byzantium, took part in several naval and land expeditions, on the last of which he died. This was his case despite the sprouting Sufi precepts of Ibrahim b. Adham which emphasized extreme asceticism, seclusion, constant meditation, contrition, sadness, divine friendship and gnosis. Next, Abdullah b. al-Mubarak (d. 181 AH/ 797 CE) is also credited with great feats of arms in the holy war against the Byzantine Christians. Although his later biographers stressed his exemplary piety and abstinence from worldly delights, he was primarily famous for his active jihad and superior physical strength. “These qualities made him a formidable warrior and a popular military leader.” At last, about Shaqiq al-Balkhi (d. 194 AH/ 810 CE), a Khorosani devotee reputed as an ardent jihadist, it has been narrated that he even resided in a fortified ribat in a city in eastern Iran, which was manned by volunteers fighting against the pagan Turks of central Asia. In the end, he was killed in action during a military expedition.
Later, approximately in the 3rd AH/ 9th CE century, some specialized ribat complexes for the Sufis were built serving exclusively as Sufi worship and learning centers. The name ribat was still preserved and was given to those newly erected Sufi institutions because the word’s etymology embodied the substance of the Sufi struggle and purpose. Maylyuda Yusupova in her paper entitled “Evolution of Architecture of the Sufi Complexes in Bukhara” wrote that in the 3rd AH/ 9th CE century, special ribats were built in Central Asia for Sufi followers. She mentioned the names of several of them in Samarkand. It is also possible that ribats were built by the Samanids in their capital at Bukhara, but there is no concrete evidence for it. “Those constructions may have been of a courtyard type, as they were genetically connected with the military fortified ribats and caravanserais, which characteristically did have that type of construction.”
The earliest reference to the concept of ribat as a Sufi institution is the one provided by Abu al-Qasim al-Qushayri in relation to Abu Yazid al-Bistami who died in 261 AH/ 875 CE. Abu Yazid al-Bistami is reported to have gone one night to a ribat in order to recollect God’s name on one of the walls of that ribat. He stayed there until dawn without uttering a word. When asked about that he answered: “(While there), there had passed through my mind a (rude) word that I once uttered in my childhood, and I was ashamed to mention God — may He be blessed and exalted.” A reference is also made to a famous early ribat in Abbadan, an island in the mouth of Shatt al-Arab that was frequented by early Sufis and ascetics, in which Sahl al-Tustari (d. 283 AH/ 896 CE), an eminent early Sufi theorist and exegete from Basrah, engaged in arduous ascetic exercises, which are said to have induced in him a vision of God’s greatest name written in the sky in green letters from east to west. Definitely, ribats as fortified military edifices, wherein some Sufis resided together with other fighting volunteers, existed much earlier than the exclusive Sufi ribats we are referring here to.
Ribats continued to exist throughout the subsequent centuries. Both their presence and importance seem did not dwindle even after the rapid rise and spread of khanqahs as more specialized and more sophisticated Sufi religious and educational institutions in the 4th, 5th and 6th AH/ 10th, 11th and 12th CE centuries. Abu Ali al-Daqqaq (d. 412 AH/ 1021 CE), a teacher of Abu al-Qasim al-Qushayri, once said that renunciation is that a person gives up this world as it is and not say: “I will build a ribat or construct a mosque.” Moreover, Abu Nasr Abd al-Rahim (d. 514 AH/ 1120 CE), a son of Abu al-Qasim al-Qushayri, is said to have preached both in a ribat and madrasah or school, as we will see later. Ribats as Sufi hospices have been mentioned as late as in the 7th, 8th and 9th AH/ 13th, 14th and 15th CE centuries. Ibn Jubayr (d. 614 AH/ 1217 CE) mentioned them, together with khanqahs, in his travel memoirs as a remarkable thing he witnessed in Damascus. As did al-Maqrizi, who died in 845 AH/ 1441 CE, mention at least twelve ribats which featured permanently in the urban morphology of Cairo together with other Sufi institutions. Shihab al-Din Umar al-Suhrawardi (d. 632 AH/ 1234 CE) spoke at length in his book “‘Awarif al-Ma’arif” about Sufi institutions and how a Sufi ought to behave when entering, while inside and when leaving them. But the author used only the term ribat in his discourses. Although he died in the 7th AH/ 13th century, he did not mention the name of khanqah, or any other name, for Sufi institutions.
As a small digression, when in one of the above referred-to accounts Abu Ali al-Daqqaq mentioned the mosque institution together with the ribat institution, that demonstrated the uninterrupted importance of the mosque in the lives, practices and teachings of the Sufis, notwithstanding the materialization and independence of their own institutions. Although the mosque and Sufi institutions were physically separated, they were spiritually united working together and supporting each other towards the same vision, objectives and goals, just as it was the case with other socio-political, educational and religious institutions. Barring a few exceptions, ideological harmony, rather than dichotomy, presided over the process of institutional decentralization in the Muslim society. This harmonious and mutually respecting and supporting relationship between the mosque institution and Sufi institutions, and between the people who were representing both the poles of the Islamic presence, was always a norm whenever and wherever authentic Sufism and the mainstream of the Islamic orthodoxy coexisted. As another illustration of the said relationship, it is narrated about a Sufi Ali b. Ahmad al-Bushanji (d. 348 AH/ 959 CE) that despite building a khanqah in Nishapur, he still frequented and stayed in mosques, and observed seclusion. Indeed, neglecting mosques and failing to perform the Jumu’ah Prayer and other congregational prayers in them, due to some substitute inventions accommodated by Sufi institutions, is a sign of pseudo Sufism. According to Ibn Ajibah (d. 1224 AH/ 1809 CE), a Sufi exegete, one of those substitute inventions was an “arba’in” invention according to which a Sufi vowed to isolate himself in a Sufi cloister for forty days intending to worship God there alone. Consequently, he misses performing Jumu’ah and other congregational prayers in mosques. This, some Sufis thought, was of virtue, but was no more than following in the footsteps of Satan. The same Sufi exegete, Ibn Ajibah, said that Islam’s “monasticism”, which according to the Prophet (pbuh) implies jihad (struggle) in the cause of Allah, is in the orbs of both mosques and Sufi institutions. It implies interacting with and guiding people principally in those two types of institutions, rather than utter withdrawal and seclusion in mountains, caves or deserts.
In the same context, it is noteworthy that the earliest books and epistles on Sufi culture and education, which were meant primarily for Sufi disciples (murids) and Sufi followers in general, such as Abu Talib al-Makki’s (d. 386 AH/ 996 CE) “Qut al-Qulub” and Abu Abdullah al-Harith al-Muhasibi’s (d. 243 AH/ 857 CE) “al-Ri’ayah li Huquq Allah”, did not make any reference to the then rising phenomenon of Sufi institutions, but they did make regular references to the Mosque institution, emphasizing its unrivaled importance in the spiritual as well as intellectual development of Sufi disciples (murids). The message was very clear, that is, come what may, the mosque institution could never be overlooked or eclipsed by any other social or religious institution. It is the most important institution in Islam; everything else comes second. More or less, the same holds true concerning the contents of other books and epistles written around the same time, such as “Kitab al-Luma’” by Abu Nasr al-Siraj al-Tusi (d. 378 AH/ 988 CE) and “al-Risalah al-Qushayriyyah” by Abu al-Qasim al-Qushayri (d. 465 AH/ 1072 CE). On that score, when Shihab al-Din Umar al-Suhrawardi discoursed about the Sufi ethics pertaining to travel and entering a city, he insisted that upon entering a city, a Sufi must go to a mosque first and pray two rak’ahs or units of prayer in it. If he goes to a city’s central mosque (jami’) for the purpose, that would be even better. Only then should a Sufi proceed to a ribat or any other available Sufi institution. For Shihab al-Din Umar al-Suhrawardi, this sequence, actually, is a sunnah (a practice of the Prophet (pbuh)) because whenever the Prophet (pbuh) returned from a journey, he would go to his mosque first. After performing a short prayer of two rak’ahs or units there, he would go to his house next. However, given that a traveling Sufi has no house in cities to which he comes, his house becomes a ribat or any other Sufi institution in those cities. Thus, after a mosque, a Sufi’s next station ought always to be a Sufi institution, which is his house. As per some accounts from the earliest days of Islam, whenever a visitor came to Madinah, the Prophet’s city, if he had an acquaintance, he would stay with him, but if he did not have anybody, he would then proceed to the suffah, a kind of a hostel in a corner of the northern side of the Prophet’s mosque where the poorest companions of the community resided, and would stay there. In a way, the Sufis followed this tradition of the Prophet’s community in Madinah.
Moreover, as examples of institutional harmony between authentic Sufism and its institutions and the rest of Muslim social, educational and religious institutions, both Abu al-Qasim al-Qushayri and Abu Hamid al-Ghazzali at some point of their energetic lives preached and taught in both government sponsored establishments and Sufi institutions some of which around their respective eras (5th and early 6th AH/ 11th and 12th CE centuries) might have been, at least partly, government sponsored too. Surely, when Abu Hamid al-Ghazzali taught in the Nizamiya school in Baghdad, and when Abu al-Qasim al-Qushayri held hadith (the Prophet’s tradition) sessions at the palace of Abbasid caliph al-Qa’im (d. 467 AH/ 1074 CE) in Baghdad, their audiences must have been numerous and wide-ranging, including government officials, the Sufis and the common herd of Muslims. What’s more, in 392 AH/ 1001 CE, a Shafi’i madrasah or school was founded for Abu al-Qasim al-Qushayri’s Sufi master and father-in-law, Abu Ali al-Daqqaq. Al-Qushayri later took it over, and it came to be known as al-Qushayri madrasah. Abu Ali al-Daqqaq, Abu al-Qasim al-Qushayri and one of the latter’s sons were all buried there. Abu Nasr Abd al-Rahim, another son of Abu al-Qasim al-Qushayri, who was not renown as a Sufi, but rather as a theologian, is reported to have preached in both a government madrasah and a Sufi institution (ribat). Abdul Qadir al-Jilani, the founding father of the Qadiriyah Sufi order, is also reported to have taught in a Hanbali madrasah in Baghdad to which a Sufi hospice was later added for him and his large family. As is Abu al-Najib Abd al-Qahir al-Suhrawardi (d. 563 AH/ 1168 CE), with whom the emergence of the great Suhrawardiya Sufi order or brotherhood is associated, reputed to have combined both the academic and Sufi careers. He taught in the Nizamiya school in Baghdad, as well as in his own madrasah which was situated next to his Sufi lodge also in Baghdad. He taught jurisprudence, hadith (the Prophet’s tradition) and Sufism.
As regards Abu Hamid al-Ghazzali and his combination of academic and Sufi careers, he firstly before converting to Sufism taught in the Nizamiya school in Baghdad. However, he later found to his surprise that he was engrossed in several studies of little value and were profitless relating to his salvation. He probed the motives of his teaching and found that in place of being sincerely consecrated to God, it was only actuated by a vain desire of honor and reputation. He felt that he was on the edge of an abyss. He then left Baghdad vowing never to return to it again. Symbolically, that also meant that he vowed never to return to his previous spiritual way of life again. Nevertheless, the longings of his heart and the prayers of his children brought him back to his country. But he returned as a transformed personality, as an illuminated Sufi. Upon return, he meant to live alone and in religious meditation. He was responsible for, and taught in, a Sufi hospice, ribat. But events, family cares and vicissitudes of little changed his resolutions and troubled his meditative calm. After all, he could not neglect his family and other social responsibilities although he had to be vigorously persuaded by his friends and well-wishers. He had to teach again in a government sponsored school, but now as a different person, as a Sufi. His new teaching engagement was inspired by his new Sufi insights and was formulated very carefully in accordance with orthodox Islam. Indeed, Abu Hamid al-Ghazzali showed both in theory and practice how compatible orthodox Islam and authentic Sufism, as well as authentic Sufi and other Muslim social, educational and religious institutions, are. He said implicitly suggesting this spiritual and institutional compatibility: “However irregular the intervals which I could give to devotional ecstasy, my confidence in it did not diminish; and the more I was diverted by hindrances, the more steadfastly I returned to it.”
 Ahmad Ibn Taymiyah, Majmu’ah al-Fatawa, vol. 6 p. 6.
 Abu Na’im al-Asfahani, Hulyah al-Awliya’ wa Tabaqat al-Asfiya’, (Beirut: Dar al-Kutub al-‘Ilmiyyah, 2002), vol. 6 p. 167-177.
 Ahmet T. Karamustafa, Sufism, the Formative Period, p. 121.
 Farid al-Din Attar, Muslim Saints and Mystics, translated into English by A. J. Arberry, (Ames, Iowa: Omphaloskepsis, 2000), p. 32-33.
 Ibid., p. 1.
 Ibid., p. 26.
 Abu al-‘Abbas al-Maqrizi, Al-Khitat al-Maqriziyyah, vol. 4 p. 281-282.
 Shamsuddin al-Dhahabi, Tarikh al-Islam, vol. 3 p. 509.
 Akram Diya’ Umari, Madinan Society at the Time of the Prophet, (Herndon: The International Institute of Islamic Thought, 1991), p. 87.
 Shihab al-Din Umar al-Suhrawardi, ‘Awarif al-Ma’arif, vol. 1 p. 267-272.
 Laith Su’ud Jassem, Al-Ri’ayah wa al-Khidamat al-Ijtima’iyyah fi ‘Asr al-Nubuwwah wa Dawr al-Mar’ah al-Muslimah fiha, in “Majallah (Journal) al-Hikmah”. 1998. Vol. 14. p. 343-413.
 Akram Diya’ Umari, Madinan Society at the Time of the Prophet, p. 92.
 Ibid., p. 93.
 Wan Noor Zeiti Binti Wan Abdul Rashid, Khanqah, A Sufi Learning Institution in Mamluk Egypt (1250-1517 C.E.), A Thesis Submitted to the International Institute of Islamic Thought and Civilization (ISTAC) in Partial Fulfillment of the M.A. Degree, Kuala Lumpur, 2002, p. 23
 Abu al-Fida’ Ibn Kathir, Tafsir Ibn Kathir, http://www.qtafsir.com/index.php?option=com_content&task=view&id=3154&Itemid=46 (accessed October 8, 2012)
 Ali Muhammad al-Sallabi, Qiyam al-Dawlah al-Ayyubiyyah, (Cairo: Dar al-Kitab al-Hadith, 2008), p. 176.
 Abu al-Qasim al-Qushayri, Lata’if al-Isharat, http://www.altafsir.com/Tafasir.asp?tMadhNo=3&tTafsirNo=31&tSoraNo=8&tAyahNo=41&tDisplay=yes&UserProfile=0&LanguageId=1 (accessed October 8, 2012)
 Alexander Knysh, Islamic Mysticism, A Short History, p. 19. Abu Abd al-Rahman al-Sulami, Tabaqat al-Sufiyyah, p. 35.
Alexander Knysh, Islamic Mysticism, A Short History, p. 21.
 Ibid., p. 32. Siraj al-Din ‘Umar al-Misri Ibn al-Mulaqqan, Tabaqat al-Awliya’, p. 44.
 Maylyuda Yusupova, Evolution of Architecture of the Sufi Complexes in Bukhara, in “Bukhara: The Myth and the Architecture,” edited by Attilio Petruccioli, (Cambridge, Massachusetts: The Aga Khan Program for Islamic Architecture, 1999), p. 121-132.
 Abu al-Qasim al-Qushayri, Al-Risalah al-Qushayriyyah, translated into English by Alexander Knysh, p. 33.
 Ibid., p. 34.
 Alexander Knysh, Islamic Mysticism, A Short History, p. 84.
 Abu al-Qasim al-Qushayri, Al-Risalah al-Qushayriyyah, p. 116.
 Siraj al-Din ‘Umar al-Misri Ibn al-Mulaqqan, Tabaqat al-Awliya’, p. 201.
 Abu al-‘Abbas al-Maqrizi, Al-Khitat al-Maqriziyyah, vol. 4 p. 302-307.
 Siraj al-Din ‘Umar al-Misri Ibn al-Mulaqqan, Tabaqat al-Awliya’, p. 196.
 Ibn Ajibah, Tafsir al-Bahr al-Madid fi Tafsir al-Qur’an al-Majid, http://www.altafsir.com/Tafasir.asp?tMadhNo=3&tTafsirNo=37&tSoraNo=57&tAyahNo=27&tDisplay=yes&Page=3&Size=1&LanguageId=1(accessed October 11, 2012).
 Abu Talib al-Makki, Qut al-Qulub, vol. 1 p. 30-82, vol. 2 p. 437. Abu Abdullah al-Harith al-Muhasibi, al-Ri’ayah li Huquq Allah, p. 503-518.
 Shihab al-Din Umar al-Suhrawardi, ‘Awarif al-Ma’arif, vol. 1 p. 308-309.
 Alexander Knysh, Islamic Mysticism, A Short History, p. 131.
 Margaret Malamud, Sufi Organizations and Structures of Authority in Medieval Nishapur, in “Sufism”, edited by Lloyd Ridgeon, (London: Routledge, 2008), vol. 1 p. 212-230.
 Siraj al-Din ‘Umar al-Misri Ibn al-Mulaqqan, Tabaqat al-Awliya’, p. 201.
 Alexander Knysh, Islamic Mysticism, A Short History, p. 180.
 Ibid., p. 193.
 Abu Hamid al-Ghazzali, The Confessions of al-Ghazzali, p. 48-53.
 Ibid., p. 53.