Close down all the opium but I had to O-P-EN
A devout Muslim, Lupe is anti-drug (opium is the scourge of the Middle East), so he closes that down. But opium is symbolic of sleep and death, which Lupe wants to get away from. So despite his anti-drug nature, he metaphorically starts (opens) the use of opium again to move in a different direction from other rappers.
But in Catholicism, OPN stand for ora pro nobis (pray for us). So maybe hes trying to say that he was praying for us.
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