Al-Ma'idah · 5:30

30. The evil prompting soul of Cain persuaded him to wrongly kill his brother, Abel. So he killed him and because of that he became one of those who are losers in this world and the Afterlife. He set a bad example and will therefore bear that burden, as well as the burden of any person who does the same until the Day of Judgement, without any reduction in the burden of those who imitate him.