I'm sorry to do this, but I have no choice.

5 seconds sound clip from the 18 Jade Arhats (1978) movie soundboard.

You can hear this line at 00:53:56 in the DVD version of the movie.

Quote context

[...]

- Are you perhaps Kung Shi-Ya?

- What's it to you?

- I owe someone a great favor. And I've been asked to replay it. You've been helping me to do that.

- Well, that's your business. But I don't see how I can help you with that.

- Well, this man said that he wants your head.

- I'm sorry to do this, but I have no choice.

- You mean that you want to kill me?

- Killing is forbidden. A true follower of Buddha may not do that.

- But even so, if you should offer to give your head in a contest, I could take that.

- A contest?

- A test of speed. The fastest wins. Do you accept that?

[...]