Companion Codices
The holy prophet initially didn’t grip minor changes during the recitation. But once it was finalised he made every effort to teach it his community who were living near him in madina and they learn it well, kept reciting before him and recorded in copies under his supervision. There left no room for any corruption because the whole community was guarding it the way we do, now.
Everyone knows abut Arza e Akhirah.