Couldn't hurt a fly.

2 seconds sound clip from the Mysterious Footworks of Kung Fu movie soundboard.

You can hear this line at 00:25:49.908 in the Blu-ray version of the movie.

Quote context

[...]

- What is he talkin' about?

- Look, punk, I don't care who it is you're workin' for...

- But you need a good beating!

- Want to fight? Right.

- My friend, you handle yourself well. But you've not seen my special monkey blow.

- So you think you're pretty good?

- Couldn't hurt a fly.

- You just look like a monkey.

- I can do that one.

- Hey, see me, I'm even better than you.

- That's the man. He's the three-eyed fellow making all the trouble.

[...]