Sir, I... I decline to answer. Respectfully.

4 seconds sound clip from the She Wore a Yellow Ribbon movie soundboard.

You can hear this line at 00:57:00.594 in the Blu-ray version of the movie.

Quote context

[...]

- All right, mister, I'll accommodate you.

- Let's step over to the corral.

- I quite agree!

- Button your shirt, Mr. Pennell!

- I thought better of you. Four years out here and still acting like a wet-eared cadet on the Hudson.

- What is this all about, Mr. Cohill?

- Sir, I... I decline to answer. Respectfully.

- It is a bitter thing indeed to learn that an officer who's had nine years' experience in the cavalry, the officer to whom I'm surrendering command of this troop in two more days,

- Should have so little grasp of leadership, as to allow himself to be chivvied into a go at fisticuffs, while Taps still sounds over a brave man's grave.

- God help this troop when I'm gone.

- You're at attention, Mr. Pennell!

[...]