"Therefore, the tormented spirit that glared out of bodily eyes, when what seemed Ahab rushed from his room, was for the time but a vacated thing, a formless somnambulistic being, a ray of living light, to be sure, but without an object to color, and therefore a blankness in itself. God help thee, old man, thy thoughts have created a creature in thee; and he whose intense thinking thus makes him a Prometheus; a vulture feeds upon that heart for ever; that vulture the very creature he creates."
Musing: Here, Ahab is linked to Prometheus - another fire image. Prometheus is the dude who stole fire from the gods to give it to mankind and is then tortured forever by the gods for the theft. Prometheus misunderstood the situation and thought he could take control away from the gods. Prometheus was also a sneaky thief, whereas Ahab blatantly tries to wrest control, and exact revenge from God/the gods. As a result, Ahab too will be tortured forever, but in this case, by the creature he has created inside of himself.