Language...
Language, too, was regarded as a sign of superiority and for this reason, the Arabs considered non-Arabs as “Ajam", which means dumb. The progress of the Islamic revolution did away with this idea and with tribal organization; with the tempestuous slogan of “There is no god but God", it made conviction and ideology prevail over all attachments to blood, territory and language.
The Prophet (S) who founded the classless and universal society of Islam, actually brought various nations together and removed their tribal hues. At a gathering of three Muslims from three countries, namely Salman from Pars, Soheib from White Romans and Bilal from Black Ethiopia, an Arab named Gheys-bin- Motateba entered and addressed the above as 'foreigners'.
The Prophet (S) said in anger: “Your father is the same and your religion is the same, and the Arabism of which you seem to be proud belongs neither to your father, nor to your mother (meaning Adam and Eve are the parents of all of you)".
Then he declared: “He who propagates the creed of tribal solidarity or fights for its sake or offers his life for it, is not of us." Nationalist forces and tribal prejudices stood stubbornly against this revolutionary message of Islam, and served as a barrier against its expansion. Those factors made the Qureish and other nations of the time take a posture against the Prophet of Islam. They protested why the Quran did not descend upon a select man of Mecca and Tayef.
As the Quran says: “And they say: Why was not this Quran revealed to a man of importance in the two towns?" (43:31) Arab tribes with their limited tribal vision wondered why the Prophet (S) did not belong to their tribes and whether he intended to establish the superiority of his own tribe. Abu-Jahl said openly: “We are the equals of the family of Abd-Manaf. In horsemanship we are their rival and in generosity their equal. How is it now that they claim prophethood and revelation?
By God, we will not accept Muhammad as a Prophet." The same racial and tribal prejudice made the Jews who had long been waiting for the advent of such a Prophet, to stand against Muhammad. Thus they refused to accept the truth and were worried why the Prophet (S) was a descendant of Ismail and not of the Israelites. So they united the pagans and polytheists against the believers in God. Kindling the flame of national feeling was the wickedest weapon of the Medinan hypocrites against Islam.