Vechān-i iṭlāq and taqyīd are the two aspects of the Divine Essence (al-Dhāt) in terms of the negation and affirmation of all considerations. The Essence of the Real (al-Ḥaqq) is an existence whose being is from itself. If it is considered in this way, it is called absolute (muṭlaq). That is, its ḥaqīqa (inner reality) is not close to everything, but is with everything. That which is not pure existence (wujūd-i baḥt) is absolute nonexistence (ʿadam-i maḥḍ). In this ḥāl (spiritual state), that which exists with Him is existent, and that which is without Him is nonexistent; how can that which is other than everything, and has no connection with anything, come together with Him?
Things that remain outside of Him are entities (aʿyān) that are not existence, but are nonexistent. If they are separated from Him, they cannot exist. Everything exists with Him, and He exists by His own Essence. His tajarrud (abstraction) of there being nothing with Him, that is, being delimited by His own limitation, then He is the One (Aḥad) with whom nothing else exists. For this reason, the verifier (muḥaqqiq, one who possesses verification) has said: He is still as He was before.
If He is considered as having something with Him, then He becomes the very delimited (muqayyid) one, who exists with Himself and is nonexistent with anything other than Himself; (the Real) manifests in its form, and thus existence is ascribed to it. If the ascription is removed, it is nonexistent in itself. This is the meaning that the Sufis have advanced in connection with tawhid (the oneness of God): tawhid is the removal of ascription. (This statement) also confirms the saying: Existence is identical with the reality of the Necessary (al-Wājib), and is distinct from the reality of everything possible. For He is something that is in excess of every essence and entity. For example, there is no doubt about the blackness of black or the humanity of human. A thing, apart from His wujūd (existence), is nonexistent without existence. (Kāshānī, 48; Jāmiʿ, 103)
Wafā (wafāʾ bi'l-ʿahd): Wafāʾ is the qalb (the heart) being alone with singularity (the oneness of Allah), persisting in witnessing His eternal light and waḥdāniyya (His oneness), and living with Him. (Lumaʿ, 302)
Wafāʾ bi'l-ʿahd (keeping one's promise): In the verse, (Allah:) "Am I not your Lord?" (they said:) "Yes, indeed" (al-Aʿrāf 7:172), the phrase refers to the acceptance of the sons of Adam of the covenant they gave to Allah, by saying "Yes, indeed," and thus their acknowledgment of His lordship. This is called wafāʾ bi'l-ʿahd.
For the common people, this means desiring the promise (of Paradise) and fearing the threat (of Hell).