Genesis 4:8-10

Now 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 killed him. Then the LORD said to Cain, “Where is Abel your brother?” He said, “I do not know. Am I my brother’s keeper?” And He said, “What have you done? The voice of your brother’s blood cries out to Me from the ground.