Al Haqq – The Truth

He whose being endures unchangingly. He whose promises and words are true.
“Therefore exalted be Allah, the King, THE REAL- ITY; there is no god but He, the Lord of the Throne of Honour!”
(23:116) The Holy Quran
“That is because ALLAH IS THE (ONLY) REAL- ITY, and because whatever else they invoke besides Him is Falsehood; and because Allah, He is the Most High, Most Great.”
(31:30) The Holy Quran
From the root
h-q-q with the
classical Arabic
connotations:
to be suitable for
wisdom, justice,
truth or fact
to be true, right,
correct, just,
to be genuine, 
to happen without
doubt.
Allah is the truth, the real, and the truly-existing. His essence is the only substance and the only reality.
His is wisdom, justice, right, rightness. He is just, right, proper, correct. The One whose essence is unavoidable.
He acts in accord with the needs of every situation. He reveals all righteousness, justice, and truth.

He makes the truth manifest by the power of His words, Who supports those whom He loves by His signs. Allah is the Truth, Al Haqq, who is worthy of being adored,

Quran tells us: The Holy Quran (22:6)