@YultGames I think that was just the writer (Toriyama?) being kinda pompous about how different Goku was from Frieza and/or Vegeta. If you watched/read through DB, you're already aware that Goku is "pure of heart".
@YultGames Good point. Goku, this is the first time you've done this, and literally only seconds ago, very obviously triggered by rage over the death of a friend. How are you certain this has anything to do with a pure heart? It definitely *appeared* to be a level of rage attained.