Genesis 4:6–9 (Wordstudy KJV):

6 And the Lord said, unto Cain, Why art thou, wroth? and why, is thy countenance,, fallen?
7 If thou [doest well,] shalt thou not, be accepted? and if, thou doest not well, sin lieth at the door., And unto,, thee shall be his desire,, and thou, shalt rule [over him.,]
8 And 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.
9 And the Lord said, unto Cain, Where is Abel thy brother?, And he said,, I know not: Am I my brother’s, keeper?,