God spit it like it's truth serum in that beer and then
He’s saying he raps the truth, as if his drink were spiked with truth serum (like in Harry Potter)
Earl may be referring to this infamous eponym hit, in which he’s filmed drinking some cocktail named “Death Juice” and rapping about girls using some dirty-minded lyrics…
Lyrically, this refers back to the line “dirty as the fucking sky that you’re praying to.” God is referenced a few lines later as a response to prayer. It’s tongue-in-cheek, though. He may be referring to himself as a god (as Jay and Kanye have recently done as well, in very different ways).
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