Genesis 4: 3-10

Time passed and Cain brought some of the produce of the soil as an offering for Yahweh, while Abel for his part brought the first–born of his flock and some of their fat as well. Yahweh looked with favour on Abel and his offering. But he did not look with favour on Cain and his offering, and Cain was very angry and downcast. Yahweh asked Cain, ‘Why are you angry and downcast? If you are doing right, surely you ought to hold your head high! But if you are not doing right, Sin is crouching at the door hungry to get you. You can still master him.’ Cain said to his brother Abel, ‘Let us go out’; and while they were in the open country, Cain set on his brother Abel and killed him. 

    Yahweh asked Cain, ‘Where is your brother Abel?’ ‘I do not know,’ he replied. ‘Am I my brother’s guardian?’ ‘What have you done?’ Yahweh asked. ‘Listen! Your brother’s blood is crying out to me from the ground.