Genesis 4:6-8

MLV(i) 6 And Jehovah said to Cain, Why are you furious? And why has your countenance fallen? 7 If you do well, will you not be accepted? And if you do not do well, sin crouches at the door. Its desire will be for you and you should rule over it.
8 And Cain told Abel his brother. And it happened, when they were in the field, that Cain rose up against Abel his brother and killed him.