Genesis 4:3-5, 15, 25

In the course of time Cain brought to the LORD an offering of the fruit of the ground, and Abel also brought of the firstborn of his flock and of their fat portions. And the LORD had regard for Abel and his offering, but for Cain and his offering he had no regard. So Cain was very angry, and his face fell.

Then the LORD said to him, “Not so! If anyone kills Cain, vengeance shall be taken on him sevenfold.” And the LORD put a mark on Cain, lest any who found him should attack him.

And Adam knew his wife again, and she bore a son and called his name Seth, for she said, “God has appointed for me another offspring instead of Abel, for Cain killed him.”