Seed/Descendant/Deliverer

God’s promise of an offspring or Savior from a woman was ironically spoken to the devil who had just succeeded in causing the first woman, Eve, to sin. God went directly to the source of the problem: Satan. God let him know that his success would be undone through the promised offspring of a woman. The promise at this point lacks any details of how this would eventually be accomplished. Many details would come later through the prophets. 

And I [God] will put enmity between you [the devil] and the woman,and between your offspring and hers; he [the promised offspring] will crush your head [take you totally out of the picture], and you [the devil] will strike his heel.”  Genesis 3:15, NIV