- How about a butt?
- I give you butt this morning. Both of you.

5 seconds sound clip from the The Bridge on the River Kwai movie soundboard.

You can hear this line at 00:05:01.773 in the Blu-ray version of the movie.

Quote context

[...]

- Those new prisoners see us digging graves, they might all run away.

- No time for jokes. Finish work! Dig, dig.

- How about putting us on sick list?

- Have a heart, captain. Put us in hospital.

- You no sick. You never sick. Why you always play sick to me?

- Don't want one of these over my head, I guess.

- How about a butt?

- I give you butt this morning. Both of you.

- That's what I mean. I want to return the favour. When a man gives me something from the goodness of his heart like you gave me that butt this morning, I remember it from the heart.

- That's why I want you to keep this lighter. Think I stole it? It belonged to that English kid we just buried over there.

- He willed that lighter to me for a favour I'd done him. Before I pass on, I want to do the same for you.

- You funny man, Shears. Okay. You go on sick list. Him too.

[...]