The words on the Iranian flag are written in Arabic, specifically in the Kufic script, even though Persian (Farsi) is Iran's official language.
The phrase repeated 22 times along the inner edges of the green and red bands is "Allāhu Akbar", which means "God is great" in Arabic. This phrase is a central Islamic declaration and was chosen to commemorate the 22nd day of the 11th month (Bahman) in the Iranian calendar—the date of the 1979 Islamic Revolution (11 February 1979).
Despite the use of Arabic script and language, the flag's design reflects deep religious and revolutionary symbolism, with the central emblem stylizing the Arabic word "Allah" and representing the five pillars of Islam.
from https://search.brave.com/search?q=What+language+are+the+letters+on+the+Iranian+flag%2C+and+what+do+the+words+say%3F&source=desktop&summary=1&conversation=08ccb9914fc319225ed8ce2837593503ec35
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