Alláh-u-Abhá is an invocation in the Bahá'í Faith, and an expression of the "Greatest Name". It is used as a greeting that Baháʼís may use when they meet each other. It can be compared to the takbīr a
The calligraphy of the Greatest Name on a metal plate at the top of the interior of the Baháʼí House of Worship in Wilmette, Illinois.
The takbīr is the name for the Arabic phrase Allāhu ʾAkbar.
Alláh-u-Abhá
…Faith, and an expression of the "Greatest Name". It is used as a greeting that Baháʼís may use when they meet each other. It can be compared to the takbīr and tasbīḥ of Islam, i.e. the Arabic phrases Allāhu ʾAkbar ("God is Great") and Subḥān Allāh ("How Pure is God"). One of the obligations Baháʼu'lláh…
A Muslim raises both of his hands to recite the takbīr in prayer.
Calligraphic Takbir in minaret of Sancaklar Mosque
Allāhu akbar in a memorial, Desouk, Egypt
Allāhu akbar in Arabic calligraphy seen on Imam Ali Mosque architecture (center of the Iwan), 1994