I take the L, transfer to the 2, head to the gates
This could possibly be a very clever double entendre. Take the L = Smoke a blunt, transfer to the 2 = get high and/or into an introspective state of mind, head to the gates = free his mind.
Depending on where in Brooklyn Kweli was, this could mean he took the L train to the 2 as the most direct way to get to the gate at Grand Army Plaza.
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