Genesis 4:1-5

Adam made love to his wife Eve, and she became pregnant and gave birth to Cain. She said, ‘With the help of the LORD I have brought forth a man.’ Later she gave birth to his brother Abel. Now Abel kept flocks, and Cain worked the soil. In the course of time Cain brought some of the fruits of the soil as an offering to the LORD. But Abel also brought an offering – fat portions from some of the firstborn of his flock. The LORD looked with favour on Abel and his offering, but on Cain and his offering he did not look with favour. So Cain was very angry, and his face was downcast.