Ima blow like I'm mothafuckin' sniffing lines
i'ma blow meaning he’s gonna blow up when he gets mainstream & more people start recognizng his music. blow also means cocaine, which also lead to “sniffin lines”. you break cocaine down in lines in order to sniff them.
To help improve the meaning of these lyrics, visit "The Heart Pt. 1" by Kendrick Lamar Lyrics and leave a comment on the lyrics box