Muhammad is the Messenger to Arabs and Non-Arabs alike
Allah said,
وَاخَرِينَ مِنْهُمْ لَمَّا يَلْحَقُوا بِهِمْ وَهُوَ الْعَزِيزُ الْحَكِيمُ
And others among them who have not yet joined them. And He is the Almighty, the All-Wise.
Imam Abu Abdullah Al-Bukhari, may Allah have mercy upon him, recorded that Abu Hurayrah said,
"We were sitting with the Prophet, when Surah Al-Jumu`ah was revealed to him;
وَاخَرِينَ مِنْهُمْ لَمَّا يَلْحَقُوا بِهِمْ
(And others among them who have not yet joined them). They said, `Who are they, O Allah's Messenger'
The Prophet did not reply until they repeated the question thrice.
At that time, Salman Al-Farisi was with us. So Allah's Messenger placed his hand on Salman, saying,
لَوْ كَانَ الاِْيمَانُ عِنْدَ الثُّرَيَّا لَنَالَهُ رِجَالٌ أَوْ رَجُلٌ مِنْ هوُلَاءِ
If faith were on Ath-Thurayya (Pleiades), even then some men or a man from these people would attain it."
Muslim, At-Tirmidhi, An-Nasa`i, Ibn Abi Hatim and Ibn Jarir collected this Hadith.
This Hadith indicates that Surah Al-Jumu`ah was revealed in Al-Madinah and that the Messenger's Message is universal.
The Prophet explained Allah's statement,
وَاخَرِينَ مِنْهُمْ
(And others among them) by mentioning Persia. This is why the Prophet sent messages to the kings of Persia and Rome, among other kings, calling them to Allah the Exalted and to follow what he was sent with.
This is why Mujahid and several others said that Allah's statement,
وَاخَرِينَ مِنْهُمْ لَمَّا يَلْحَقُوا بِهِمْ
(And others among them who have not yet joined them), refers to all non-Arabs who believe in the truth of the Prophet.
Allah's statement,
وَهُوَ الْعَزِيزُ الْحَكِيمُ
(And He is the Almighty, the All-Wise), asserts that He is Almighty and All-Wise in His legislation and the destiny He appoints.
Allah's statement,
ذَلِكَ فَضْلُ اللَّهِ يُوْتِيهِ مَن يَشَاء وَاللَّهُ ذُو الْفَضْلِ الْعَظِيمِ