Bismillah.
The ground of unification is the 69th ground or field out of the 'Hundred Fields Between Man and God' - a teaching attributed to Khwaja Abdullah Ansari, a famous Persian Sufi and poet of Herat (1006 - 1089 CE).
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The Ground of Unification (tawhid) arises from the (68th) Ground of Exile (Ghurba). Unification is:
(1) to say One
(2) to see One and
(3) to know One.
As God Almighty says: "So know that there is no God but God."
(1) 'To say One' is the beginning of all science, the gateway to all worldly and spiritual knowledge, and the partition between friend and foe. The profession of faith (in divine Oneness = Unification) is the banner, Sincerity the foundation (it is set upon), and Faithfulness its precondition. The profession (of Unification) has three outward and inward aspects:
i. To bear witness that God, the Most Exalted, is Uniquely One in Essence, exempt from association with any spouse, progeny, partner or associate. May He be Magnified and Exalted!
ii. To bear witness that God is Uniquely One in His Attributes, for in these no one bears Him any resemblance. They are His attributes and beyond our reason; the manner and quality of His attributes are incomprehensible and cannot be encompassed (by rational thought), being beyond imagination. He has no associate or likeness (amongs created things) in these Attributes. May He be Magnified and Exalted!
iii. To bear witness that God is Uniquely One in His pre-eternal Names. Whereas these Names can be ascribed to Him in reality, to others they are something borrowed and derivative. Although His created beings also have 'names', His Names are properly Real, being Eternal and anterior a parte ante to creation, and worthy of Him, while the names of created beings are temporal, in keeping with their contingent nature suitable to them. His truly proper Names are 'Allah' and 'Rahman' alone; by these (two) Names no other being may be addressed.
(2) 'To see Him as One' is in (regard to):
i. His decrees
ii. His allotments and
iii. His bounties.
(i) 'To see Him as One and Unique in His decrees' is (the recognition) that, in the allotment of providence, He is One and Unique in His comprehensively infinite pre-eternal Knowledge and all-embracing pre-eternal Wisdom. None but Him has the knowledge and wisdom to realize this. Vision of this is the fruit of wisdom; true realization of this is the fruit of wonderment; the furtherance of this is the fruit of power - which none but Him possesses!
(ii) 'To see Him as One and Unique in His allotments' is (the recognition) that His boons to creation are meted out each according to his proper share and best interest, and provided at the appropriate time.
(iii) 'To see Him as One and Unique in His bounties' is (the recognition) that He alone, in His singularity, is the Provider. He is the Giver and none else. No one but Him is deserving of gratitude and acknowledgement; His is the Power and the Might, and none else but Him possesses the wherewithal to withold or dispense bounty.
(3) 'To know Him as One' is in one's
i. service
ii. 'spiritual interactions' and
iii. will and aspiration.
(i) In service, it is to abjure leadership, to observe sincere truthfulness and to control (stray) thoughts.
(ii) In one's spiritual interactions, is to purify one's innermost consciousness, realize (the essence of) the recollection of God, and to steadfastly maintain one's confidence (in God's grace).
(iii) In will and aspiration; it is losing sight of everything but Him, forgetting everything save Him, and gaining deliverance through the heart's emancipation, from everything save Him.
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FROM: An essay by A.G. Ravan Farhadi in 'The Heritage of Sufism'. Published by Oneworld Oxford.
Pic: Ansari's Shrine Complex in Gazargah, Afghanistan.Related Lisan al-Din post: Abdullah Ansari's "Hundred Grounds"