A very short compilation on a very common word... common, at least, among Bahá’ís.
Definition
Nearly every reference found in the authoritative texts to the Arabic phrase ‘Alláh–u–Abhá’ describes it as “…a greeting…”
- “Greeting (noun)
- the act or words of a person who greets.
- a friendly message from someone who is absent: a greeting from a friend in another country.
- greetings, an expression of friendly or respectful regard: ‘Send my greetings to your family.’ ”
- “Greetings are often, but not always, used just prior to a conversation.”
Usage
Let him, then, repeat six times the greeting “Alláh-u-Abhá”….
The Prayer for the Dead, Bahá’u’lláh, Prayers and Meditations by Bahá’u’lláh, p. 260
The use of “Alláh-u-Abhá” in the East is, generally speaking, confined to a greeting. It is not said at the end of prayers and the Guardian feels that the less it is used freely in public by the Bahá’ís in the West (before strangers) the better, as it gives a very peculiar impression of us, and makes us seem like some strange Oriental sect.
Shoghi Effendi through his Secretary, Principles of Bahá’í Administration, p. 16
Description
Concerning your question regarding the “Greatest Name”: The Greatest Name is an invocation which means “O Thou of Glories!” The word “Bahá”, or “Glory”, is a reference to Bahá’u’lláh. The Greatest Name is a distinctive mark of the Cause and a symbol of our Faith. The term of “Alláh-u-Abhá”, on the other hand, is a form of Bahá’í greeting, and means “God the All Glorious.”
From a letter written on behalf of Shoghi Effendi to an individual believer, December 8, 1941; Lights of Guidance, p. 266
The Greatest Name is the Name of Bahá’u’lláh. Yá Bahá’u’l-Abhá is an invocation meaning: “O Thou Glory of Glories!” “Alláh-u-Abhá” is a greeting which means: “God the All-Glorious”. Both refer to Bahá’u’lláh. By Greatest Name is meant that Bahá’u’lláh has appeared in God’s Greatest Name, in other words, that He is the Supreme Manifestation of God.
From a letter written on behalf of Shoghi Effendi to the National Spiritual Assembly of Australia and New Zealand, December 26, 1941; Lights of Guidance, p. 266 and Letters from the Guardian to Australia and New Zealand, p. 41
“Alláh-u-Abhá” is an Arabic phrase meaning “God the All-Glorious”. It is a form of the Greatest Name of God…. In Islam there is a tradition that among the many names of God, one was the greatest; however, the identity of this Greatest Name was hidden. Bahá’u’lláh has confirmed that the Greatest Name is “Bahá”. The various derivatives of the word “Bahá” are also regarded as the Greatest Name….
Author unknown; note from The Kitáb-i-Aqdas, p. 180
History
The greeting “Alláh-u-Abhá” was adopted during the period of Bahá’u’lláh’s exile in Adrianople.……
Author unknown; continuation of above note from The Kitáb-i-Aqdas, p. 180
It was in this period that the greeting of “Alláh-u-Abhá” superseded the old salutation of “Alláh-u-Akbar,” and was simultaneously adopted in Persia and Adrianople….
Shoghi Effendi, God Passes By, p. 176
The closing years at Adrianople were also marked by significant internal developments. The appellations ‘Bábí’ and ‘the people of the Bayan’ gave way to ‘Bahá’í’ and ‘the people of Bahá’; the greeting ‘Alláh-u-Akbar’ (God is the Greatest) was replaced by ‘Alláh-u-Abhá’ (God is the Most Glorious), although it ought to be noted that both of these greetings as well as another, ‘Alláh-u-Ajmal’ (God is the Most Beauteous), were sanctioned by the Báb.
H.M. Balyuzi, Bahá’u’lláh– The King of Glory, p. 250