I was not yet conscious of the fact that, in the time of the Prophet Muhammad, this classical Arabic couldn't possibly have been spoken by all Arabs across the Arabian Peninsula.
The soldiers of the Arab Islamic armies who conquered and Arabised the populations of the Fertile Crescent, North Africa, Malta, and even parts of Andalusia, also did not speak this classical Arabic, for the simple reason that they all brought their own linguistic varieties with them from their home regions.
In fact, larger homogeneous language areas do not exist and never did. Not in Arabia, nor anywhere else.
Maintaining unique linguistic elements
It should not be a surprise that the populations outside of the Arabian Peninsula that were Arabised, maintained some elements of their native languages — from Aramaic in the Fertile Crescent area and Coptic in Egypt, to the Berber languages of North Africa.
These substrates still survive in their contemporary vocabularies and in some of their dialect structures.
Those who believed that Arabic dialects were deviations from the classical standard language, al-Arabiya al-Fusha, which is the unifying language of all Arabs,were opposed to dialect studies and their exploration.
They believed that such studies had sinister and Orientalist-inspired intentions to foment division among the Arabs, and this was one of the reasons why Arabic dialect research, in general, was not highly regarded in the Arab world.
This is changing, however.
It has become fully acceptable to socially communicate in colloquial Arabic, even on official occasions. It has also become more or less accepted that communicating in colloquially-tinted Arabic is far more appealing than using classical Arabic, which is never naturally spoken in any Arab home.
Several mainly Western academics have in the meantime published impressive studies, like the monumental Arabic dialect encyclopaedias of Peter Behnstedt and Manfred Woidich.
Incorporating a variety of cultures
If you look at history, "the Arab nation" absorbed many people who were not originally Arab but were later Arabised. As a result, the Arabs of today came to retroactively incorporate a great variety of cultures from outside the Arabian Peninsula, like those of Mesopotamia, Greater Syria, Egypt and North Africa.
