Genesis 4:6-8

Then the LORD said to Cain, “Why are you angry? And why has your countenance fallen? If you do well, will not your countenance be lifted up? And if you do not do well, sin is crouching at the door; and its desire is for you, but you must master it.” Cain told Abel his brother. And it came about when they were in the field, that Cain rose up against Abel his brother and killed him.