It's not important. Good night.
3 seconds sound clip from the The Exorcist movie soundboard.
You can hear this line at 01:28:43 in the Blu-ray version of the movie.
Quote context
[...]
- Did Regan know a priest was coming over?
- No.
- Did you know my mother died recently?
- It's not important. Good night.
- Here, take it and just don't... Okay. Um.
- What should I say? I don't know. Just talk to your daddy. Anything you want.
- All right... Tell him what you've been doing and how you're feeling and like that.
[...]