Knowledge ('ilm) means information obtained through the human senses or through the Revelations or inspiration of God. It is also used to denote information that is in agreement with facts or realities, and to denote understanding something with its real, whole meaning and content. In addition, we come across usage of this term in the simple sense of thinking, under-standing, comprehension, and conclusions drawn as a result of such mental processes. Sometimes the word knowledge can even mean familiarity.
Although it is well known which aspect of the term knowledge in Islamic Sufism is most relevant in the context of this book, we deem it useful to mention some secondary matters, such as the different types of knowledge and its sources.
Knowledge, first of all, is dealt with in two categories: knowledge without means or knowledge that is had without being acquired, and knowledge that is acquired through some means.
Every living being has its own peculiar characteristics and potentials. These characteristics and potentials are the sources of certain, innate knowledge, knowledge a creature has without having to acquire it. (The modern scientific term for this kind of knowledge is instinct.) A human being's being able to sense and perceive a lack of air, thirst, hunger, grief and joy, etc., a baby's knowledge of how to nurse, a bird's knowledge of how to fly and build nests, a fish's knowledge of how to swim, young animals' knowledge of how to avoid dangers, in short, these types of knowledge, knowledge of how to deal with the necessities of life, fall into the category of knowledge without means.
Knowledge acquired through the internal and external senses is included in the second category. Knowledge concern-ing the physical world is usually obtained through the five external senses-sight, hearing, smell, taste, and touch-while knowledge about the metaphysical or incorporeal realm of existence is acquired through internal senses-the mind and heart with their faculties of thought, reason, spiritual discovery and experience, intuition, etc.
As for the sources of knowledge or means of acquiring it, these consist of three, according to Islam:
- The five external senses, provided they are sound.
- True reports, of which there are two kinds: reports unanimously given by a group of truthful people of such a number that it is inconceivable that they have agreed to lie, and reports given by the Messengers of God, whom He has sent with special messages.
- The third source of knowledge is reason. Axiomatic knowledge and the knowledge reached by using the mental faculties are included in this kind of knowledge.
Knowledge is also divided into two groups: that which is acquired through the mental faculties, and that which is reported knowledge. The first can be divided up into three categories:
- Knowledge of such matters as health and education, which in Islam are regarded as incumbent upon every individual or a group of people in the community, according to the time and conditions.
- Another kind of knowledge acquired through the mental faculties is knowledge of which Islam disapproves. Sorcery, divination and occult sciences are of this kind.
- Sciences, such as geometry, mathematics, medicine, physics, chemistry, and history are included in the third category, the study of which Islam regards as obligatory on the community in order to discover God's laws of the creation and operation of the universe and for the well-being of the community.
Reported knowledge is of two kinds: knowledge based on spiritual discovery and inspiration and knowledge concerning Islam and Islamic life. The second kind has been separated under four heads:
- The knowledge of the fundamental principles, which include knowledge of the Qur'an, Sunna (the Prophet's way of life, sayings, and confirmations), the consensus of the scholars (ijma') and analogy or deductive reasoning. These are the sources upon which the rules of the Shari'a are based.
- The knowledge of the subdivisions, which includes the knowledge of worship (the Prescribed Prayer, the Prescribed Alms-giving, Fasting, Pilgrimage and so on), the daily life of the believers, marriage and relevant matters, such as divorce and alimony (civil law), and legal penalties (criminal law), etc.
- Primary sciences, such as language, grammar, meaning, composition, and eloquence, which are ways to properly understand the religious sciences, such as Hadith (the sayings of the Prophet), the interpretation of the Qur'an, and jurisprudence.
- The complementary or secondary sciences, i.e. the sciences additional to the sciences of the Qur'an. They consist of sciences relating to the wording and composition of the Qur'an, such as phonetics and recitation; the sciences pertaining to its meaning, such as interpretation and exegesis, and those relating to its commandments, such as the abrogating and the abrogated, the general and particular, the explicit and implicit, the real or literal and the metaphorical or allusive, the succinct and the detailed, the clear and the ambiguous, the direct and firm and the allegorical.
As for reported knowledge based on spiritual discovery and inspiration, it has also been dealt with under two heads: the knowledge that occurs in one's heart as a gift from God, and the knowledge that arises in the conscience. What we will study among the topics of the "Emerald Hills of the Heart" is this kind of knowledge. Whether it is of the kind occurring in one's heart as a gift from God or of the kind arising in the conscience, this knowledge is and must be based on the Qur'an and the Sunna. Any knowledge one finds in one's heart or conscience which has not been filtered through these two pure sources is not reliable. It cannot be binding knowledge for either the individuals themselves or others, it cannot be considered as authentic, sound knowledge. This important point has been stressed by many great Sufi leaders. For example:
Junayd al-Baghdadi says: "All the ways that do not end in the Prophet are closed and do not lead to the truth." He also reminds us: "Anyone who does not know the Book and the Sunna is not to be followed as a guide."
Abu Hafs explains: "Anyone who does not continually control him or herself in the light of the Book and the Sunna cannot be regarded as belonging to this way."
Abu Sulayman al-Darani warns: "I admit the truth of whatever occurs to the heart only provided it is confirmed by the Book and the Sunna."
Abu Yazid al-Bistami admonishes: "I struggled against my carnal self for almost thirty years and did not find anything more difficult for it to accept than the objective criteria of the Book and the Sunna. You should not be misled by anyone, even if they work wonders like flying through the air, rather you should consider their care in observing the limits set up by the Shari'a and following the commandments of the Book and the Sunna."
Abu Sa'id al-Harraz sums up the matter: "Any intuitive knowledge which is not compatible with the spirit of religion is false."
Abu al-Qasim Nasrabadi teaches: "The essence of the Sufi way is strict adherence to the Book and the Sunna, holding back from the misleading inclinations of the carnal self and innovations in religion, being able to overlook the faults of others, not becoming negligent in one's daily recitations to glorify and praise the Almighty, being strict in fulfilling the religious commandments without applying special exceptions, and refraining from personal, insubstantial opinions regarding religion."
The Sufi leaders give knowledge precedence over the spiritual state of the Sufis, because that state depends on knowledge. Knowledge is the heritage of the Prophets, and the scholars are the heirs thereto. The Prophetic saying, "The scholars are the heirs of the Prophets," is the highest of the ranks recognized for scholars.
The knowledge of the truth or knowledge that leads to the truth is the life of the heart, the light of the eye, the cause of the expansion of the breast (with peace, exhilaration, and spiritual happiness), the stimulus to activate reason, the source of pleasure for the spirit, the guide of those bewildered as to which way to follow, the intimate friend of the lonely, and an invaluable table of heavenly foods offered on the earth and one to which the angels show great respect.
Knowledge is an important step toward belief, a standard to distinguish between guidance and error and between certainty and doubt, and a Divine mystery manifesting the truly human aspects of a person.
There is no exaggeration in the following saying of a friend of God:
A human being is truly human with knowledge;
But without knowledge is entirely bestial.
Action without knowledge is purely ignorance;
So, O friend, you cannot find the Truth without knowledge.
By knowledge, the Sufis mean, rather than the familiarity that is reached with the mind, hearing and sight, the light and radiation that come from the realms beyond the material world and have their source in God's Knowledge. This light pervades the spirit and bursts like flowers in the meadows of the innermost faculties of the person, and swells and flows in the gifts of the All-Eternal One. In order to be able to receive this Divine gift, one should, first of all, turn with all one's inner world to the Eternal Sun and, freed from the influences of the body and carnal pleasures, lead a life at the level of heart and spirit, and open one's breast to God, the Truth, with belief, love, and attraction, and then one should be able to rise to a level where one can be taught by God through inspiration.
As declared in the Divine declaration (18:65), We taught him knowledge of a special kind from Our Presence, God-inspired knowledge is the rain of mercy that pours down into the depths of a person's inner world from the Realm of the Holy Presence- the Realm where those who are the nearest to God experience His Holy Presence-without any intermediary and veils. Deep devotion to God, sincere adherence and loyalty to Him as well as the Messenger, being sincerely well-pleased with whatever God decrees or causes to happen for one and trying to please Him, the sincerity and purity of intention in one's acts or doing whatever one does only to please Him and because He wants us to do it, and having a heart pursuing certainty in the matters of belief over and over again-all this is what is required to be rewarded with God-inspired knowledge, especially in abundance.
Since the Prophets received Divine Revelation and were taught by Him, their knowledge is a God-inspired knowledge that comes from Him without any intermediary. As for the knowledge of purified, saintly scholars and other saintly persons, this is also a God-inspired knowledge, the only difference being that the source is the rays of light of the Prophetic knowledge. Khadr is regarded as the foremost one in receiving this knowledge. However, he can only be so regarded for a certain period of time and spiritual rank and for the state particular to him. In certain particular matters, some people may be superior to those who are superior to them in general terms. Similarly, in certain particularities of God-inspired knowledge, Khadr is superior to those who are greater than him. He is in no way superior to either the Prophet Moses, upon him be peace, or the other great Messengers.
As a Messenger charged with teaching people God's commandments and guiding them in their lives so that they could attain happiness in both worlds, the Prophet Moses knew God's commandments concerning the human individual and social life and the sensitive relation between them and the outward and inward aspects or dimensions of things. But, Khadr's knowledge is restricted to the inward dimension of things. He points to this difference in his conversation with Moses: "Moses! I have a kind of knowledge which God has taught me and you do not possess, while you have another kind of knowledge which God has taught you and I do not possess."
In conclusion, God-inspired knowledge is the kind of knowledge which one cannot acquire by studying or being taught by others. It is a special gift from God and a kind of illumination, from a sacred source, that one finds in one's heart. Rather than being the kind of knowledge about the Creator acquired by studying creation and which therefore leads from the created to the Creator, it is a kind that pours from the Maker to the conscious "works" of His art. It is even regarded as the emergence in the human spirit of the knowledge about some mysteries pertaining to God, the Truth, as special gifts from Him.
Anyway, it is always God Who knows best the truth in every matter.
 Abu Hafs 'Amr b. Salama al-Haddad of Nishabur (d. 879). A blacksmith of Nishabur, visited Baghdad and met al-Junayd who admired his devotion. He also encountered al-Shibli and other Sufis of the Baghdad school. Returning to Nishapur, he resumed his trade and died there in 879. (Trans.)
 Abu Sulayman al-Darani (d. 830). An ascetic known for his weeping in worship. He was held in honour by the Sufis and was (called) the sweet basil of hearts (rayhan-i dilha). He is distinguished by his severe austerities. He spoke in subtle terms concerning the practice of devotion. (Trans.)
 Abu Yazid al-Bistami (d. 873): One of the greatest Sufi masters. Junayd said: "Abu Yazid holds the same rank among us as Gabriel among the angels." His life was based on self-mortification and the practice of devotion. (Trans.)
 Abu Sa'id Ahmad ibn 'Isa al-Kharraz of Baghdad, a cobbler by trade, met Dhu al-Nun al-Misri and associated with Bishr al-Khafi and Sari al-Saqati. Author of several books including some which have survived, the date of his death is uncertain but probably occurred between 892 and 899. (Trans.)
 Abu al-Qasim Ibrahim ibn Muhammad ibn Mahmud al-Nasrabadi: One of the famous Sufi masters and scholars. (Trans.)
 Al-Bukhari, al-Jami' al-Sahih, "'Ilm," 10.
 Khadr is he with whom the Qur'an recounts (18: 60-82) the Prophet Moses made a travel to learn something of the spiritual realm of existence and the nature of God's acts in it. It is controversial whether he was a Prophet or a saint with special mission. It is believed that he enjoys the degree of life where one feels no need for the necessities of normal human life. (Trans.)
 The writer refers to the significant encounter and experience between Moses and Khadr that is recounted in the Qur'an, 18:60-82. (Trans.)
 Al-Bukhari, "Tafsir," 18:4.