Genesis 3:15
And I will put enmity between you and the woman,
What it says
God places enmity between the serpent and the woman, and between their offspring; the conflict is cast as mutual striking, with the serpent reaching for the heel and the offspring for the head.
What it is doing
It defines the lasting struggle that follows the serpent's deception.
In context
14So the LORD God said to the serpent: 15And I will put enmity between you and the woman,