Delilah is the seductive lower nature that lulls the awakened power to sleep in the lap of sense-pleasure, and the sleep itself is the drop from alert awareness into unconsciousness. The 7 locks are the sun-force, the number 7 marking the full complement of spiritual energy crowning the head, and cutting them is the severing of the higher current at its source. Once the flowing power is shorn from the crown, the strength that came through it drains away.
The strong man is not overpowered by force but coaxed into slumber and quietly cut off from the light above, and the vitality that made him mighty leaves the moment his connection to it is severed.
Delilah: the seductive lower nature that lulls the higher self asleep in the lap of the senses
7 locks: the sevenfold solar life-force crowning the head, the full stream of spiritual energy
Head: the crown of the body where the higher current enters and the awakened power is worn