"Abha” is the Greatest Name of God revealed to us in this age. God, the Infinite, who is above ascent or descent, beyond perception, knowledge or comprehension, is nameless as far as man is concerned. A name of anything expresses the qualities or manifestations of that thing. The essence of nothing whatever is known. The essence of everything is nameless. Therefore, the Greatest Name of God is the Name of His highest manifested attributes. The highest appearance of Himself which can be perceived by any creature anywhere in existence—that Name is "Abha." Its meaning is Splendor or The Most Shining Glory. It is The Most Holy Outpouring, The Radiant Energy from the Unseen, Unknown Infinite Entity.
Anything to appear must have some one to see it. No creature of existence can ever see the Infinite and, therefore, it is impossible for the Infinite to have a name; but the Highest Quality or Manifestation of that Infinite, which can be perceived by any creature in existence, can have a name and that name is "Abha." It is Light.
"Baha" is the same name on a different plane. "Baha" is the name of the Manifestation in humanity to human kind. "Abha" is the name of that Manifestation in His Heavens or Spiritual Spheres.
"Abha" is the highest, superlative Manifestation that can be perceived only by the highest possible existences.
God, the Infinite, is the Pre-Existent, which does not mean as to time, but as the Cause of causes. He is not a part of existence. He, Himself, is outside of all existences, but manifests Himself through all existence as the light from a flame manifests itself throughout a crystalline room. He, unknown in Himself, manifests His Glory through His chosen and prepared Representative in existence. That Representative among mankind is Baha’u’llah, the Glory of God, the Word Incarnate, the visible humanized Word. Above it is the Glory of God, the Word Invisible. Light Itself.
"Allah-u-Abha” is the Greeting of the Greatest Name. It is the Greeting of the Supreme Kingdom. "Ya Baha’u’l-Abha" is an exclamation. It means: O Thou, the Glory of the Most Glorious!
(Star of the West, vol. 4, no. 11, September 27, 1913)