Well, here's half an answer.
4 seconds sound clip from the Snow White and the Seven Dwarfs (1938) classic radio play.
You can hear this line at 00:57:08 in the radio play.
Quote context
[...]
- Is it true that it wasn't published until the Grimm Brothers came along?
- Yes, just about a hundred years ago.
- Jacob Grimm was a very learned man, a scientist. You'd hardly think he'd go in for fairy tales.
- Age, language, race make no difference. What's the secret?
- Well, here's half an answer.
- You mean that's a common denominator?
- The same level you speak of knows nothing of sophistication and distinction.
- It's where all of us are simple and naive, without prejudice and bias. We're friendly and trusting.
[...]