Cops undercover doing some illegal street buys (from the movie RoboCop (2014)):
— Where the hell you get a gun like that, Jerry?
— I can get you two whole crates full, man.
— Two crates? No disrespect, J, but how a clown like you get so much product, man?
— What's it matter where it comes from?
— Why it matters, we don't want no dirty guns, Jerry. These guns got bodies on 'em, Jerry?
— Yo, look, they're clean, all right? You gonna buy this shit or not?
— Why you acting so nervous, man?
— You fishin' on us, Jerry?
— What'd you say?
— You think he fishin', D?
— I think he's fishin' on us.
— Yo, what the hell are they talkin' about, man?
— Hey, let me see your phone.
I searched online and couldn't find a thing about this expression.