You'd better lay off him, Kid.
2 seconds sound clip from the Johnny Guitar (1954) movie soundboard.
You can hear this line at 01:36:14.779 in the Blu-ray version of the movie.
Quote context
[...]
- So it's the Johnny boy, huh?
- I will.
- What are you gonna tell me, Kid?
- Well, look at Mr. Guitar. All dressed up and looking mighty dangerous.
- I'm too scared, now that you got a gun.
- You'd better lay off him, Kid.
- I wasn't thinking of you hurting him.
- You mean he might, uh, shoot himself in the leg, trying to draw?
- No. But if I were you, I wouldn't fool around with Johnny Logan.
- Well! Pleased to meet you, Mr. Logan.
- I never shake hands with a left-handed draw.
[...]