Genesis 4:1
And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD.
>>>And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD.<<<
Eve mistakenly believed that Cain (the firstborn) was the fulfillment of the prophecy of Genesis 3:15 - but he was a murderer.
“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.”
Her first mistake was thinking that Cain was from the seed of a woman . . . he was from the seed of the man.
Jesus Christ came from the seed of the woman whereby he avoided the curse of Adam.