`“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. “

“In Islám 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.”

- Note 33 from the The Kitáb-i-Aqdas,

The Greatest Name symbol is based on the Arabic root word of “Bahá” meaning Glory, splendor or light.