- This letter, you wrote it, didn't you?
- Yes. That's a letter I wrote my wife. How'd you get it?

12 seconds sound clip from the Heroes of the East (1978) movie soundboard.

You can hear this line at 00:49:03.692 in the DVD version of the movie.

Quote context

[...]

- Well now, my name's Sanzu.

- I've heard of you.

- That's good.

- This gentleman is a famous Japanese teacher, and he taught me the secrets of Ninjitsu.

- These men are some of the best fighters in Japan. We've come here to accept the challenge you made.

- Challenge? But I never challenged you men, though. You've made a mistake.

- This letter, you wrote it, didn't you?

- Yes. That's a letter I wrote my wife. How'd you get it?

- Your wife is Japanese, and so any challenge to her, is a challenge to us, as well.

- It's between me and her.

- As from now on, she is no longer your wife.

- Huh? You... What was that?

[...]