I found it, I found it!

3 seconds sound clip from the 'Twas the Night Before Christmas (1974) movie soundboard.

You can hear this line at 00:06:42.786 in the Blu-ray version of the movie.

Quote context

[...]

- Come on, old Kris Kringle, down the Milky Way

- Of course, this is only a small model with the children singing, I have to make a big one. Big enough for Santa to see it and hear it.

- I move to authorize construction at once.

- Second.

- All those in favor? And don't you dare say no, McDavitt.

- Aye.

- Carried.

- You may build your clock, Mr. Trundle. And may the enchanting tones of its melody soar to the pinnacle of the celestial heights where... Oh, heck, get started.

- I found it, I found it!

- Dear Editor, Santa Claus is a fraudulent myth rooted in unconscious fantasies and emerging as a deceitful lie. P.S. The reindeer are phony too. Signed, all of us.

- No wonder Santa's angry. Who would send him a letter like that?

- Big words. It sounds like the mayor.

- Long words. Long words. Long words.

[...]