Although broadly sharing the same film unit (director, editor, etc.), two different versions of the film (one in English and the other in Arabic), were shot simultaneously, scene by scene. Two completely different sets of actors shared the same set; once a scene had been established, one actor would play a character in one language, and then the whole scene reshot with his corresponding number speaking in the other language. The lone exception in the cast being Andre Morell who is credited as Abu-Talib in both versions. The main (English) version was released as "The Message", while the Arabic version became "Al-Risalah".
Production stopped when the financiers withdrew their support, leaving cast and crew stranded for two weeks in Morocco (in a hotel with broken air conditioning; they slept under wet towels). Financing was eventually supplied by none other than Libyan leader Muammar Gaddafi.
In accordance with Muslim beliefs, Mohammed could not be depicted on screen nor could his voice be heard. This rule extended to his wives, his daughters and the four Caliphs (Abu Bakr, Omar, Othman, Ali). This left Mohammed's uncle Hamza as the central character (played by the Egyptian actor Abdallah Gheith).
It took 4 and a half months to build the ancient city of Mecca.
At its initial release, this movie was banned from many Middle-Eastern countries because the religious leaders didn't like the idea of having the Prophet Mohammed's story being made into a motion picture.