Thy seed - her seed - the curse of the Fall

 At Fall of Adam God cursed the serpent for beguiling Eve and fracturing the perfect creation of humanity. Results from this curse fell upon all human conception since that very "original sin". Human conception, from that point on, was tainted from birth, born with a sinful nature and polluted with sin. Genesis described this very conception in the promise to the serpent as, "thy seed".

In contrast to the curse of the Fall where humanity was tainted with sin you also have "her seed" which indicates the biblical conception of the son of God in the prophetically fulfilled virgin birth. By nature all conception is formed from the seed of man "except" the only seed of a woman in existence, Christ, the Anointed One, and Savior and redeemer of humanity.

Genesis 3:15...And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.

In the conception of Christ you find the power to bruise, crush, and destroy the power of the Devil. In the crucifixion of Christ you see the suffering of a Savior where the heel of Christ was bruised, where He actually shed blood, and died only to reveal His supremacy and power over death. Such power from a promised, crucified, and risen Christ bruises the authority of the serpent and offers deliverance from the acts of sin and the very nature of sin inherited from Adam's curse of the Fall.