Genesis 4:6-10

6And the LORD said to Cain, Why art thou angry? and why is thy countenance fallen? 7If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And to thee shall be his desire, and thou shalt rule over him.12

8And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.

9And the LORD said to Cain, Where is Abel thy brother? And he said, I know not: Am I my brother’s keeper? 10And he said, What hast thou done? the voice of thy brother’s blood crieth to me from the ground.3