How is “swear to” used?

In Dune: Part Two (2024), one line is: “I swear to you, I wasn't aware of any of this.”

Which movie is “swear to” from?

The clip at the top of this page is from Dune: Part Two (2024).

to say that sth is definitely true

informal · Heard in 38 movies

Definitions from the Oxford Advanced Learner's Dictionary, 9th edition

I swear to you, I wasn't aware of any of this.

Said in 8 films · #1