Genesis 4:5-8

5but he did not have regard for Cain and his offering. Cain was furious, and he looked despondent.

6Then the Lord said to Cain, “Why are you furious? And why do you look despondent?

7If you do what is right, won’t you be accepted? But if you do not do what is right, sin is crouching at the door. Its desire is for you, but you must rule over it.”

8Cain said to his brother Abel, “Let’s go out to the field.” And while they were in the field, Cain attacked his brother Abel and killed him.