"When Hallaj's love for God reached its utmost limit, he became his own enemy and naughted himself.

He said, "I am Haqq," that is, "I have been annihilated; God remains, nothing else."

This is extreme humility and the utmost limit of servanthood.
It means, "He alone is." To make a false claim and to be proud is to say,
"Thou art God and I am the servant."

For in this way you are affirming your own existence, and duality is the necessary result... Hence God said, "I am God."
Other than He, nothing else existed.

Hallaj had been annihilated, so those were the words of God.

Pharaoh said, "I am God," and became despicable.
Hallaj said "I am Haqq," and was saved.

That "I" brought with it God's curse, but this "I" brought His Mercy, oh friend!
To say "I" at the wrong time is a curse, but to say it at the right time is a mercy.

Without doubt Hallaj's "I" was a mercy, but that of Pharaoh became a curse.
Note this!

(William C. Chittick, Fihi ma Fihi, in 'The Sufi Path of Love: The Spiritual Teachings of Rumi', pp. 191-193)