"And the LORD God said to the serpent, Because you have done this, you are cursed above all cattle, and above every beast of the field; on your belly shall you go, and dust shall you eat all the days of your life: And I will put enmity between you and the woman, and between your seed and her seed; it shall bruise your head, and you shall bruise his heel."
This promise comes just after the fall of man, and predicts the coming of the "seed of the woman" implying the virgin birth. The virgin born child would be a male who would trample the serpent under his feet. John, in Revelation, lets us know that the serpent is Satan, and Matthew informs us that the boy is Jesus. When Jesus was crucified the serpent bruised "his heel." However, when Jesus rose he bruised [crushed] the serpents offspring of death.