Genesis 4:1-3

Now the man had relations with his wife Eve, and she conceived and gave birth to Cain, and she said, “I have gotten a manchild with the help of the LORD.” Again, she gave birth to his brother Abel. And Abel was a keeper of flocks, but Cain was a tiller of the ground. So it came about in the course of time that Cain brought an offering to the LORD of the fruit of the ground.