I like the sound of the phrase, but I’d never heard it before. After a month or so, I was curious if the phrase was just a Nicki-ism or if it’s common vernacular. I Googled the words and sure enough, ‘kick rocks’ apparently it’s fairly common. Couldn’t find an origin to the phrase other than a vague reference to ‘kick rocks’ being something an 80s kid would say, so now I’m wondering if it is a regional phrase to the Sacramento area or if it’s very common and just wasn’t in use by my particular circle of peers. I remember a lot more “Get bent!” and “Piss off!” instead.