Genesis 4:2-6

And again, she gave birth to his brother Abel. Now Abel was a keeper of flocks, but Cain was a cultivator of the ground.

So it came about in the course of time that Cain brought an offering to the Lord from the fruit of the ground.

Abel, on his part also brought an offering, from the firstborn of his flock and from 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 became very angry and his face was gloomy.

Then the Lord said to Cain, “Why are you angry? And why is your face gloomy?