In Arabic

In the Qur'an, the word ʿarab does not appear, only the nisba adjective, ʿarabiyyun: The Qur'an is referring to itself as ʿarabiyyun "Arabic" and mubinun "clear". 

al-´a`rābu ´ašaddu kufran wa-nifāqan "the Bedouin are the worst in disbelief and hypocrisy".

Based on this, in early Islamic terminology, ʿarab referred to sedentary Arabs, living in cities such as Mecca and Medina, and ʾaʿrāb referred to the Arab Bedouins, carrying a negative connotation due to the Qur'anic verdict just cited. Following the Islamic conquest of the 8th century, however, the language of the nomadic Arabs came to be regarded as preserving the highest purity by the grammarians following Abi Ishaq, and the term kalam al-ʿArab "language of the Arabs" came to denote the uncontaminated language of the Bedouins.

Cf. the modern toponyms Algarve and Arava

 <sup>See Also: 

The History of Cordoba, Spain. 

The Similarities of Spanish and Arabic Languages.  

Ancient Arabic Texts at www.sacred-texts.com</sup>