넘기다 is making something go over or past, and the verb in front says how. Physically that is sweeping hair back off the forehead, or passing an object on to the next person. Figuratively, 받아넘기다 is fielding something awkward and brushing it aside, and 팔아넘기다 is selling someone off or handing them over, which in these lines covers both a trafficking operation and playfully throwing a friend under the bus.