The language of the sedentary and urban population
It should be known that the usual form of address used among the urban and sedentary population is not the old Mudar language nor the language of the (present-day) Arab Bedouins. It is another independent language, remote from the language of the Mudar and from the language of presentday Arab Bedouins. It is more remote from the former (than from the latter).
It is obvious that it is an independent language by itself. The fact is attested by the changes it shows, which grammatical scholarship 1353 considers solecisms. Moreover, it is different in the various cities depending on the differences in terminologies used by their (inhabitants). 1354 The language of the inhabitants of the East differs somewhat from that of the inhabitants of the West. The same applies to the relationship of the language of the Spaniards to either of them. All these people are able to express in their own language whatever they want to express, and to explain their ideas. That is what languages and dialects are for. Loss of the vowel endings does not disturb them, as we have stated in connection with the language of present-day Arab (Bedouins).1355
The fact that (the language spoken in present-day cities) is more remote from the ancient (Arabic) language than the language of present-day Arab Bedouins is conditioned by the fact that remoteness from the (ancient Arabic) language is due to contact with non-Arabs. More contact with non-Arabs means greater remoteness from the original language. For, as we have stated, a (linguistic) habit results only from instruction, and the (new) habit is a mixture of the ancient (linguistic) habit of the Arabs and the later (acquired linguistic) habit of the non-Arabs. 1356 The longer people listen to non-Arab (speech) and the longer they are brought up in such a condition, the more remote from the ancient habit do they become.
In this connection, one may compare the cities of Ifriqiyah, the Maghrib, Spain, and the East. In Ifriqiyah and the Maghrib, the Arabs had contact with the non-Arab Berbers who constitute the bulk of the population ('umran) of (those countries). Hardly any city or group was without (Berbers). Therefore, the non-Arab (element) there gained preponderance over the language of the Arabs. Thus, there originated another, mixed language in which the non-Arab (element) was preponderant, for the reasons mentioned. (The language spoken there) is more remote from the ancient language (than other dialects).
Likewise, in the East, the Arabs gained superiority over the Persian and Turkish nations there. They had contact with them. These languages circulated among them in (the speech of) farmers, peasants, and captives whom they used as servants, wet nurses, and foster mothers. Thus, their (linguistic) habit was corrupted. With that, their language (also was corrupted, and) eventually it came to be another language.
The same (happened to) the Spaniards in their relations with the non-Arab Galicians and European Christians. The entire urban population of those zones came to speak another language, one peculiar to them and different from the language of the Mudar. It also showed (dialectical) differences within itself, as we are going to mention.1357 In a way, it was another language (and no longer Arabic), in as much as the habit of it became firmly rooted among those people (in Spain).
"God creates whatever He wishes." 1358