You can't study the layout of the bridge after dark. You've got to get there before sundown.

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

You can hear this line at 02:00:30.649 in the Blu-ray version of the movie.

Quote context

[...]

- What are you doing? I didn't give orders for a halt.

- We all need it.

- We're still five hours' fast march from the objective. Maybe six. Come on.

- If you keep walking on that foot, you'll bleed to death.

- You're going to leave me here.

- If you stop, we stop.

- You can't study the layout of the bridge after dark. You've got to get there before sundown.

- But, sir, when the job's done, who knows if we can return by this route or whether we could find you if we did?

- If you were in my shoes, I wouldn't hesitate to leave you, and you know that.

- He doesn't know it, but I do. You'd leave your own mother here if the rules called for it.

- You'll go on without me. That's an order.

[...]