Wrestler of oppressors

The Holy Quran reviewed a number of previous nations that disbelieved in the messengers of their Lord and the calls of his prophets and denied the other, and corrupted the earth and rose very high, God Almighty inflicted on each of them his worldly punishment of destruction and promised them the torment of the other, which is more severe and shameful

All of this was revealed 1400 years ago to the Prophet peace be upon him and in a nation the overwhelming majority of illiterate people, so where does he get these details if not a revelation from the Lord of the worlds ?