I'm afraid I'll have to disagree with you again.

4 seconds sound clip from the Miracle on 34th Street (1947) movie soundboard.

You can hear this line at 00:35:12 in the Blu-ray version of the movie.

Quote context

[...]

- A famous example is that fellow, uh, uh... Well, I can't think of his name, but for years he's insisted he's a Russian prince.

- There's been all kinds of evidence to prove him wrong, but nothing has shaken his story.

- Is he in an institution?

- No.

- He owns a famous restaurant in Hollywood and is a highly respected citizen.

- I've made a great study of abnormal psychology and I've found from experience that when a fixed delusion is challenged, the deluded is apt to become violent.

- I'm afraid I'll have to disagree with you again.

- If you tell Kris there is no Santa Claus, I grant you he'll argue the point, but he'll not become violent.

- His whole manner suggests aggressiveness.

- Look at the way he carries that cane... and he's never without it.

- I know Kris always carries a cane, but surely you're not implying he'd use the cane as a weapon.

[...]