Genesis 4:8-10
New King James Version (NKJV)

8 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.

9 Then the Lord said to Cain, “Where is Abel your
brother?”

He said, “I do not know. Am I my brother’s
keeper?”

10 And He said, “What have you done? The voice of
your brother’s blood cries out to Me from the ground.