At that time, those who had not attained this perfection fell into two groups.
First were the unbelievers—the Jews and Christians who would not accept Allah’s guidance.
Second were the others, the non-Arabs, who did not share with the Arabs the sound natural disposition upon which they had been created. In fact, the overwhelming majority of non-Arabs in those days—Persians and Romans alike—were idolaters. Thus the Sacred Law came commanding adherence to those early forerunners who had embraced the guidance Allah approved for them, and commanding opposition to everyone else, whether because of open disobedience, inherent deficiency, or even the likelihood of such deficiency.
When therefore the Shariʿah forbids imitating the non-Arabs, the ban covers the practices of unbelieving non-Arabs, past and present, and it also includes any practices adopted by Muslim non-Arabs that were unknown to the earliest generations. Likewise, the term “Arab jāhiliyyah” applies both to what the Arabs practiced before Islam and to the same practices to which many of them have since returned.
Whoever among the Arabs imitates the non-Arabs is counted with them, and whoever among the non-Arabs imitates the Arabs is counted with them. For this reason, the sons of Persia who attained knowledge and faith did so only by following the upright religion along with all that it entails—chief among those requisites being mastery of the Arabic language. Conversely, whatever shortcomings have befallen the Arabs arise solely from their failure to uphold these requisites, or from their conformity with non-Arabs in matters where the Sunnah requires them to differ. That is one aspect of the issue.
Moreover, since Allah revealed His Book in the Arabic tongue and appointed His Messenger to convey it