Do yourself a favor. Hit him.
5 seconds sound clip from the Training Day (2001) movie soundboard.
You can hear this line at 01:08:45 in the Blu-ray version of the movie.
Quote context
[...]
- Hey, Jake, here. Hey, come sit down. Sit down. Right here.
- I'll tell you a secret. When you kill someone on duty, they have to be your slave in the afterlife.
- There you go. Start an entourage.
- What, you want me to shoot him?
- Yeah.
- Come on, kid. Do me a favor. Come on.
- Do yourself a favor. Hit him.
- All right, I'll... I'll shoot him.
- Go.
- Pow!
[...]