وَأَنَّ نُبُوَّتَهُ لَا تَخْتَصُّ بِالْعَرَبِ
His prophethood is not restricted to the Arabs.
Some historical opponents sought to restrict the mission to its first Arab audience. That reading conflicts with the universal language of revelation and the wider scope of the prophetic call. The first audience of a message is not necessarily its final boundary.
For example, a rule can be announced first in one city while applying to a much wider population. The location of its initial announcement does not determine its full scope. In discussing messengership, the decisive question is the group actually addressed by its authoritative revelation, not the prophet's initial social setting.