Genesis 4:6-9

So YAHWEH said to Cain, “Why are you so angry and bothered? If you offer what is right, won’t you be accepted? But if you refuse to offer what is right, sin, the predator, is crouching in wait outside the door of your heart. It desires to have you, yet you must be its master.” One day Cain said to his brother, “Let’s go out into the field.” When they arrived at the field, Cain rose and attacked and killed his brother Abel. Then YAHWEH said to Cain, “Where is your brother Abel?” He answered, “How do I know? Am I my brother’s keeper?”