11 Now before they do that, I am telling you that you should kill your brother. That way your sister will be left for you, and his sister will be cast away."
12 And Satan departed from him. But the devil remained behind in Cain's heart, and frequently aspired to kill his brother.
Chapter LXXVII - Cain, 15 years old, and Abel 12 years old, grow apart.
1 But when Adam saw that the older brother hated the younger, he endeavored to soften their hearts, and said to Cain, "O my son, take of the fruits of your sowing and make an offering to God, so that He might forgive you for your wickedness and sin."
2 He said also to Abel, "Take some of your sowing and make an offering and bring it to God, so that He might forgive you for your wickedness and sin."
3 Then Abel obeyed his father's voice, took some of his sowing, and made a good offering, and said to his father, Adam, "Come with me and show me how to offer it up."
4 And they went, Adam and Eve with him, and they showed him how to offer up his gift on the altar. Then after that, they stood up and prayed that God would accept Abel's offering.
5 Then God looked at Abel and accepted his offering. And God was more pleased with Abel than with his offering, because of his good heart and pure body. There was no trace of guile in him.
6 Then they came down from the altar, and went to the cave in which they lived. But Abel, by reason of his joy at having made his offering, repeated it three times a week, after the example of his father Adam.