The slaughter runs through the lower mind, the land in bondage that holds the light captive, and it takes the firstborn: the first strength of the flesh, the mind and nerves and emotions, the strongest of the low thoughts. In meditation the solar energy rises from the solar plexus to the pineal gland and cuts these burdensome thoughts down where they sit. The ruling ego on its throne loses its heir, and even the animal drives penned in the body lose their first increase.
Midnight is the lowest turn of the dark cycle, the point on the clock the old sky-readers marked as Virgo, the virgin place where the sun is born again. At that turn the ascending light empties the carnal mind of its firstborn thoughts and the ruler who lived by them is left with nothing to command.
Egypt: the lower, carnal mind, the seat of bondage that holds the inner light captive
Firstborn: the first strength of the flesh, the mind and nerves and emotions, the strongest of the low thoughts
Pharaoh: the ego, the ruler enthroned over the lower mind
Midnight: the lowest point of the dark cycle, the Virgo turn where the inner sun is born again
Cattle: the animal drives penned within the body