وَمَا كَانَ رَبُّكَ مُهْلِكَ الْقُرَى حَتَّى يَبْعَثَ فِي أُمِّهَا
And never will your Lord destroy the towns until He sends to their mother town i.e., Makkah --
رَسُولاً يَتْلُو عَلَيْهِمْ ايَاتِنَا
a Messenger reciting to them Our Ayat.
This indicates that the Unlettered Prophet, Muhammad was sent from the Mother of Cities as a Messenger to all cities and towns, Arab and non-Arab alike.
This is like the Ayat;
لِّتُنذِرَ أُمَّ الْقُرَى وَمَنْ حَوْلَهَا
so that you may warn the Mother of Towns and all those around it. (6;92)
قُلْ يَأَيُّهَا النَّاسُ إِنِّى رَسُولُ اللَّهِ إِلَيْكُمْ جَمِيعًا
Say;"O mankind! Verily, I am sent to you all as the Messenger of Allah." (7;158)
لااٌّنذِرَكُمْ بِهِ وَمَن بَلَغَ
That I may therewith warn you and whomsoever it may reach. (6;19)
وَمَن يَكْفُرْ بِهِ مِنَ الاٌّحْزَابِ فَالنَّارُ مَوْعِدُهُ
but those of the sects that reject it, the Fire will be their promised meeting place. (11;17)
وَإِن مِّن قَرْيَةٍ إِلاَّ نَحْنُ مُهْلِكُوهَا قَبْلَ يَوْمِ الْقِيَـمَةِ أَوْ مُعَذِّبُوهَا عَذَابًا شَدِيدًا
And there is not a town but We shall destroy it before the Day of Resurrection, or punish it with a severe torment. (17;58)
Allah tells us that He will destroy every town before the Day of Resurrection, as He says;
وَمَا كُنَّا مُعَذِّبِينَ حَتَّى نَبْعَثَ رَسُولاً
And We never punish until We have sent a Messenger. (17;15)
Allah has sent the Unlettered Prophet to all the towns (all of mankind), because he has been sent to the Mother of Cities, their source to which they all return.
It was recorded in the Two Sahihs that the Prophet said;
بُعِثْتُ إِلَى الاَْحْمَرِ وَالاَْسْوَد
I have been sent to the red and the black.
Prophethood ended with him, and there is no Prophet or Messenger to come after him, but his way will remain as long as night and day remain, until the Day of Resurrection.
Allah also tells that;
وَمَا كُنَّا مُهْلِكِي الْقُرَى إِلاَّ وَأَهْلُهَا ظَالِمُونَ
And never would We destroy the towns unless the people thereof are wrongdoers