Then, it is to become annihilated (fanāʾ) in ḥaqqa'l-yaqīn (ḥaqqa'l-yaqīn). (Manāzil, 25)
ʿIlm al-yaqīn (certainty through knowledge) is attained by investigation and proof; ʿayn al-yaqīn (certainty through direct vision) is attained by unveiling and inspiration; and ḥaqqa'l-yaqīn is realized by shedding the earthly human qualities and by the seeker of union reaching this degree.
Fāris says: In ʿilm al-yaqīn there is no doubt or distress. ʿAyn al-yaqīn is the knowledge that Allah entrusts to the secrets (ʿilm al-yaqīn-ʿayn al-yaqīn-ḥaqqa'l-yaqīn).
It is the knowledge that Allah has deposited (entrusted) in the secrets. If knowledge does not possess the quality of yaqīn (possessor), there is doubt in it. If knowledge possesses the quality of yaqīn, there is no doubt in it. Ḥaqqa'l-yaqīn is the reality (ḥaqīqa) and foundation of what ʿilm al-yaqīn and ʿayn al-yaqīn indicate (indicate).
Junayd says: Ḥaqqa'l-yaqīn is for the servant to be immersed in this knowledge. For the servant to witness the unseen just as clearly as he sees visible things, thereby confirming his knowledge of the unseen and giving direct reports from there... ʿIlm al-yaqīn is a state of separation (farq); ʿayn al-yaqīn is a state of union (jamʿ); ḥaqqa'l-yaqīn is the state of union of unions (jamʿu'l-jamʿ) in the language of tawḥīd (tawḥid).
ʿIlm al-yaqīn is knowledge established by proof.
ʿAyn al-yaqīn is knowledge given by witnessing and unveiling.
Ḥaqqa'l-yaqīn is knowledge attained by witnessing the One who is sought (Allah). (Iṣṭilāḥ, 539)
For the one who finds direction and stability with Allah (findallāh), in Allah (fillāh), with Allah (billāh), and together with Allah (maʿallāh), there must be a sign that can be attributed to yaqīn in this state. For this sign is unique to him and pertains only to him. This is ʿilm al-yaqīn. The witnessing of this sign, its connection to yaqīn, and its being made specific to that person is ʿayn al-yaqīn. Wisdom (ḥikma) must be necessary in this ayn and this knowledge. Knowledge only acts upon what must necessarily be acted upon; ayn only investigates what must be investigated.
This, then, is ḥaqqa'l-yaqīn, which is necessary for both knowledge and ayn. Yaqīn is everything that has found stability and firmness. There is no wavering in anything pertaining to the Real (ḥaqq) or to creation (khalq). Knowledge pertaining to yaqīn exists as knowledge, ayn, and ḥaqq (essence and reality). That is, the necessity of wisdom is nothing other than the Divine Essence. Knowing the Divine Essence as yaqīn is outside of ḥaqqa'l-yaqīn. In this matter, what is required of us is silence and not delving into it, for we do not know the Divine Essence. Then comes knowledge attributed to yaqīn but not witnessed. Ayn cannot be attributed to yaqīn. It has a sovereignty over the world, but one must completely refrain from delving into those matters. (Futūḥāt, II, 560)
The perfection (kamāl) of iḥsān (iḥsān) is to purify action from seeking recompense, from pursuing an aim, or from ostentation. This is the meaning of ikhlāṣ (ikhlāṣ). The perfection of iḥsān is only attained by witnessing the Divine Presence in all acts of worship with the light of insight (baṣīra)... This iḥsān is the iḥsān that occurs for the continuity of the state of presence, which is the continuity of servanthood (ʿubūdiyya) without the intrusion of stray thoughts or attachment to others. This presence, according to them, is the connection (nisba) that reaches the Prophet and is called ḥaqqa'l-yaqīn; and in reality (in reality), it is interpreted as the attribute of the sālik (traveler) being annihilated (fanāʾ) in the attribute of the Real and subsisting (baqāʾ) with Him, not only in knowledge but also in direct witnessing and state. (Bughyat, 26)
Ḥaqqa'l-yaqīn is to witness the reality of the Real in the station of unity (aḥadiyya). (Kāshānī, 60; Jāmiʿ, 81)
The levels of ʿilm al-yaqīn, ʿayn al-yaqīn, and ḥaqqa'l-yaqīn that we have mentioned are the ultimate knowledge to be gained from books. It is almost impossible to reach even a small part of them, let alone all, by working a lifetime. I have seen that children who are people of this path among our brothers, by studying these books in a short time, have reached levels that men could not reach in forty or fifty years of effort. Yet those men were the ones who enabled those children to enter the tariqa. However, they themselves remained in their place by traversing the path, while those children continued to study and understand the books of reality. Since the men fell short of their goal, the children became shaykhs in reality, and the elders became like children. (Marātib, 10)
Know that for the members of this exalted Tariqa, the outward tawḥid (manifest) during the path is divided into two: tawḥid al-shuhūd and tawḥid al-wujūd.
Tawḥid al-shuhūd is the witnessing of the One, meaning that the sālik sees that there is nothing in existence other than the One. Tawḥid al-wujūd is for the sālik to know and believe that existence is one, and to believe that all other existents are non-existent, and to think so. While believing that nothing exists besides Him, he also believes that they are the loci of manifestation and places of disclosure of this One. Tawḥid al-wujūd is of the category of ʿilm al-yaqīn, while tawḥid al-shuhūd is of the category of ʿayn al-yaqīn. This tawḥid is one of the essential (necessary) principles of this tariqa. Thus, the state of fanāʾ cannot be realized without tawḥid al-shuhūd, nor can ʿayn al-yaqīn be attained without tawḥid al-shuhūd. The witnessing of aḥadiyya in its totality requires seeing nothing but Him. Tawḥid al-wujūd is not like this, i.e., it is not necessary. ʿIlm al-yaqīn can be attained without this maʿrifa. For ʿilm al-yaqīn, in its initial aim, does not require the negation of everything other than Him. This state, when the knowledge of the One dominates by way of overpowering, necessitates the elimination of everything other than Him. (Maktūbāt, I, 56)
The meaning of the phrase "Ana'l-Ḥaqq" (I am the Real) is this: The Real is He, not I. For that person, not seeing his own nafs (lower self), affirms Him. Otherwise, he does not say he is the Real because he sees his nafs as a being separate from the Real. For such a statement is kufr (disbelief). The absence of affirmation does not necessarily entail negation, and this is not exactly tawḥid al-wujūd. But it can be said:
The absence of affirmation does not absolutely (absolutely) require negation. For this station is the station of bewilderment (ḥayra). Here, all judgments fall away. In the phrase "Subḥānī..." (in the phrase), it is not the speaker himself, but the Real who is being glorified. For the nafs has completely fallen from his consideration. No judgment applies there.
Such words and similar ones appear from those in the station of ʿayn al-yaqīn. This station is the station of bewilderment. When one rises from this station to the level of ḥaqqa'l-yaqīn, he refrains from such words and does not exceed the bounds of moderation. (Maktūbāt, I, 57)
ʿIlm al-ẓāhir (outward knowledge) - ʿilm al-bāṭin (inward knowledge)
It can be said: According to the views of this exalted group (the Sufis), yaqīn is of three levels: ʿilm al-yaqīn, ʿayn al-yaqīn, and ḥaqqa'l-yaqīn. Thus, they have said that ʿilm al-yaqīn is like inferring the existence of fire by knowing the existence of smoke, ʿayn al-yaqīn is seeing the fire itself, and ḥaqqa'l-yaqīn is being realized with the fire itself. So, when the vision of the heart is lost, how can ʿayn al-yaqīn be realized? Since vision is absolutely lost, how can the consensus of the shaykhs be correct?
In response, I say: Most likely, what the questioner means by consensus is the consensus of the early shaykhs (mutaqaddimīn). The later shaykhs (muta'akhkhirīn) have ruled otherwise and have allowed the vision of the heart.
In my humble opinion, the mentioned ruling is not established. All three levels they have explained are included in ʿilm al-yaqīn. For the field of inference has not yet been left, and knowledge has not passed to ayn. The example given for ʿayn al-yaqīn, seeing the fire, is in reality seeing the smoke that is presented as evidence for the existence of fire. Just as this is included in ʿilm al-yaqīn, so too is inferring the existence of fire by knowing the existence of smoke. In this station, inferring the existence of fire by seeing the smoke is the same. This second yaqīn, due to the strength of the evidence, is more perfect than the first. For there, knowing is the evidence, while here, seeing is the evidence.
Similarly, in ḥaqqa'l-yaqīn, realization is not with the fire, but again with the smoke, and inference is again made from it. This yaqīn is more complete and perfect than the two types of yaqīn previously described. For this is inference from what is smoke to the existence of fire. This is the clear difference between the macrocosm (āfāq) and the microcosm (anfus). Allah the Exalted has said: "We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth." (al-Fuṣṣilat 41:53)
ʿIlm al-yaqīn is by proof (burhān), ʿayn al-yaqīn is by witnessing the essences (aʿyān), and ḥaqqa'l-yaqīn is by unveiling the forms of the essences. Similarly, what is obtained from mass-transmitted knowledge is also ʿilm al-yaqīn. Seeing this knowledge is ʿayn al-yaqīn; being immersed in it is ḥaqqa'l-yaqīn. (Qawīnīn, 87)
Yaqīn is of three types: ʿilm al-yaqīn is for the common people, ʿayn al-yaqīn is for the elect, and ḥaqqa'l-yaqīn is for the elect of the elect. (Jāmiʿ, 61)
(See also: ilhām; kashf/kushūfāt; muḥāḍara-mukāshafa-mushāhada; yaqīn)