A spitting blunt is when a marijuana cigar (blunt) is "spitting" out marijuana when you inhale on it. It is common curtosy to let the person you are passing the blunt to know it is "spitting". This can sometimes be difficult if your own your last hit and it "spits" on you. In this case, you coughingly say "its spittin".
Spittin’ Gorilla Fire
Meaning when a rapper goes extremely hard in the studio spitting their rap lyrics.
When a rap Artist puts their mind in a gorilla-mode Spitting straight fire.