Genesis 4:1-9

And Adam knew Chava, his wife, and she conceived and gave birth to Cain saying, “I have gained a man with God.” She gave birth again, this time to his brother, Abel. Abel became a shepherd while Cain was a worker of the soil. An era ended. Cain brought the fruit of the ground as an offering to God. Abel also offered some of his first born from the fattest ones. And God was pleased with Abel and his offering, but Cain’s offering did not please God. Cain became furious and he hid his face. And God said to Cain, “Why are you angry? Why do you hide your face? If you do well, won’t you be accepted? And if you do not do well then sin is waiting at the door and will devour you. You may rule over him." And Cain spoke with his brother Abel, and when they where in the field Cain rose up against his brother and killed him. And God said to Cain, “Where is your brother Abel?” And Cain responded, “I do not know. Am I my brother’s keeper?” [JPS translation]