By the 2nd century AH, the language had been standardized by Arabic grammarians and knowledge of Classical Arabic became an essential prerequisite for rising into the higher classes throughout the Islamic world, as it was the lingua franca across the Middle East, North Africa, and the Horn of Africa, and thus, the region eventually developed into a widespread state of diglossia. Consequently, the classical language, as well as the Arabic script, became the subject of much mythicization and was eventually associated with religious, ethnic, and racial conflicts, such as the rise of many groups traditionally categorized under the broad label of al-Shu'ibiyya (roughly meaning "those of the nations", as opposed to Arab tribes), who, despite the remarkable differences in their views, generally rejected the stressed and often dogmatized belief that the Arabs, as well as their language, were far superior to all other races and ethnicities, and so the term later came to be applied pejoratively to such groups by their rivals. Moreover, many Arabic grammarians strove to attribute as many words as possible to a "pure Arabic origin", especially those in the Qur'an. Thus, exegetes, theologians, and grammarians who entertained the idea of the presence of "impurities" (for example, naturalized loanwords) in the Qur'an were severely criticized and their proposed etymologies denounced in most cases. Nonetheless, the belief in the racial and ethnic supremacy of the Arabs and the belief in the linguistic supremacy of Arabic did not seem to be necessary entailments of each other.